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Mugil migration studies - MUGIL PROJECT - Université Montpellier 2

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Homepage:<br />

www.mugil.univ-montp2.fr<br />

Coordinator:<br />

J. Panfili (IRD)<br />

DELIVERABLE 4<br />

<strong>MUGIL</strong><br />

Main Uses of the Grey mullet as Indicator<br />

of Littoral environmental changes<br />

2006 - 2009<br />

February 2008<br />

Summary<br />

Deliverable 4 focuses on discussions around<br />

the <strong>migration</strong> <strong>studies</strong> on <strong>Mugil</strong> cephalus,<br />

mainly concerning the application of otolith<br />

chemistry. WS3 has defined guidelines for<br />

<strong>studies</strong> on <strong>migration</strong> using otolith<br />

microchemistry in order to follow standard<br />

protocols.<br />

<strong>Mugil</strong> <strong>migration</strong> <strong>studies</strong><br />

European<br />

Commission<br />

INCO-CT-2006-026180<br />

<strong>MUGIL</strong><br />

Tomás J., Anastasopoulou K., Berrebi P., Cowley P.D.,<br />

Darnaude A., Diouf P. S., Durand J.-D., Flores-Hernandez D.,<br />

Morales-Nin B., Tzeng W.-N., Wang C.-H., Whitfield A.K., Panfili J. 1,2,3<br />

1<br />

Addresses at the end of the document.<br />

2<br />

<strong>MUGIL</strong> Deliverable 4 follows the <strong>MUGIL</strong> Workshop 3 held in <strong>Montpellier</strong> (France); 26-28 September<br />

2007 (see Annexure 1).<br />

3<br />

Image on cover: www.fao.org<br />

INCO-CT-2006-026180 1 <strong>MUGIL</strong> Deliverable 4 - Feb. 2008


Contents<br />

1. INTRODUCTION ....................................................................................................................................... 3<br />

2. USE OF OTOLITHS FOR <strong>MUGIL</strong> CEPHALUS MIGRATION STUDIES.......................................... 3<br />

3. OTOLITH PROCESSING FOR THE STUDY OF <strong>MUGIL</strong> CEPHALUS MIGRATIONS .................. 4<br />

3.1. FISH COLLECTION AND PRESERVATION ................................................................................................. 4<br />

3.2. OTOLITH REMOVAL AND PRESERVATION .............................................................................................. 4<br />

3.3. OTOLITH PREPARATION ........................................................................................................................ 6<br />

3.3.1. OTOLITH PREPARATION: WHOLE OTOLITH ............................................................................................ 6<br />

3.3.2. OTOLITH PREPARATION: TRANSVERSE SECTIONS .................................................................................. 7<br />

3.4. OTOLITH CHEMICAL ANALYSIS ........................................................................................................... 10<br />

3.4.1. WHOLE OTOLITH ANALYSIS: SB-ICPMS ............................................................................................ 10<br />

3.4.2. SURFACE ANALYSIS: ELECTRON PROBES WDS ................................................................................... 11<br />

3.4.3. SURFACE ANALYSIS: LA-ICPMS........................................................................................................ 11<br />

3.5. DATA TREATMENTS FOR OTOLITH MICROCHEMISTRY ......................................................................... 11<br />

4. GENERAL CONCLUSIONS AND RECOMMENDATIONS.............................................................. 13<br />

5. REFERENCES .......................................................................................................................................... 13<br />

6. AUTHOR ADDRESSES ........................................................................................................................... 15<br />

7. ANNEXURE 1 – WS3 AGENDA ............................................................................................................. 16<br />

INCO-CT-2006-026180 2 <strong>MUGIL</strong> Deliverable 4 - Feb. 2008<br />

Page


1. Introduction<br />

<strong>Mugil</strong> cephalus is a diadromous fish species that migrates between continental and marine<br />

environments during its life cycle: juveniles and sub-adults grow in freshwater and brackish water<br />

habitats (estuaries and lagoons). Adults undertake off-shore <strong>migration</strong>s to sea for spawning, usually in<br />

the form of large schools (Thomson, 1955; Bacheler et al., 2005).<br />

The aim of this deliverable is to define the best method for otolith collection, storage, preparation<br />

and microchemical analysis to study the transhaline <strong>migration</strong>s of grey mullets. The guidelines<br />

presented here will enable all future researchers to follow the same standard protocols for <strong>migration</strong><br />

<strong>studies</strong> involving otolith microchemistry in M. cephalus, thereby allowing global comparisons on this<br />

subject.<br />

2. Use of otoliths for <strong>Mugil</strong> cephalus <strong>migration</strong> <strong>studies</strong><br />

Otolith microchemistry has proved successful in resolving habitat occupation between freshwater<br />

and seawater environments by diadromous fish, such as salmonids (Kalish, 1990; Volk et al., 2000;<br />

Arai et al., 2007), eels (Jessop et al., 2002; Tzeng et al., 2003; Daverat et al., 2005) and shads<br />

(Thorrold et al., 1998; Tomás et al., 2005). Otolith microchemistry has also been successfully applied<br />

to the identification of saline habitats occupied by flathead (grey) mullet <strong>Mugil</strong> cephalus but these<br />

<strong>studies</strong> are scarce and almost completely confined to Taiwan (Chang et al., 2004a; Chang et al.,<br />

2004b). While catadromy was supposed to be obligatory for M. cephalus these <strong>studies</strong> have shown<br />

that it is only a potential strategy for newly recruited fry. Indeed, otolith microchemistry has shown<br />

that some individuals avoided entering continental waters and continued moving between estuaries<br />

and the sea. In the absence of detailed <strong>studies</strong> on saline habitat use by M. cephalus from other parts of<br />

the world, it already appears that otolith microchemistry constitutes a very efficient approach to<br />

identify and determine the regional range of <strong>migration</strong> of the species.<br />

Otolith microchemistry has also brought new evidences regarding nursery fidelity by M. cephalus,<br />

again in the waters of Taiwan. In an attempt to study fidelity to nursery areas by M. cephalus, otolith<br />

trace elemental composition was used as an indicator to discriminate the juveniles from various<br />

estuaries of Taiwan (Wang et al., 2006). Out of the twelve elements (Li, Na, Mg, K, Mn, Fe, Ni, Cu,<br />

Zn, Sr, Ba, and Pb) analysed from the otoliths of juvenile mullet, five elements (Mn, Ni, Zn, Sr, and<br />

Ba) were found to be significantly different between estuaries. The canonical discriminant analysis<br />

also indicated that 10 of 12 elemental ratios (except Li/Ca and Cu/Ca) played a significant role in the<br />

discrimination of juvenile M. cephalus among the estuaries. Among the elements, Mn/Ca, Ni/Ca and<br />

Zn/Ca contributed approximately 49.8 % in the first canonical function of the discrimination, while<br />

Ba/Ca and Sr/Ca contributed 32.9 % in the second function. As a result, 84 % of the early juveniles<br />

could be assigned to their recruited estuaries with their otolith chemical signatures, indicating that<br />

elemental composition in the otolith can be used as a natural tag to trace their nursery areas (Wang et<br />

al., 2006).<br />

While the use of otolith microchemistry seems promising for the study of M. cephalus <strong>migration</strong>s,<br />

several constraints exist in the use of this technique. Otoliths are often purer carbonates than other<br />

calcified structures (Campana, 1999) and the elemental signatures that are used in otoliths to<br />

discriminate between water streams, coastal waters, etc. are in the order of ppm or ppb. Thus, it is<br />

critically important to avoid otolith contamination by external elements (often extremely ubiquitous)<br />

during otolith extraction, manipulation and preparation. Moreover, the high number of analytical tools<br />

used for these <strong>studies</strong> are also sources of differences in the results (Campana et al., 1997).<br />

The purpose of <strong>MUGIL</strong> WS3 was to identify the critical steps in otolith processing which could<br />

lead to alterations in otolith composition and minimise the sources of contamination at each step. The<br />

usefulness of several otolith analysis techniques for describing M. cephalus <strong>migration</strong>s was also<br />

compared and the most valuable analytical instruments were identified and listed by the <strong>MUGIL</strong><br />

INCO-CT-2006-026180 3 <strong>MUGIL</strong> Deliverable 4 - Feb. 2008


consortium. Therefore, WS3 aimed to develop a standardised protocol and method for the application<br />

of otolith microchemistry to the study of M. cephalus <strong>migration</strong>s.<br />

3. Otolith processing for the study of <strong>Mugil</strong> cephalus<br />

<strong>migration</strong>s<br />

Foreword: During otolith processing, contact between the otolith surface and metallic tools, bare<br />

hands or any liquid of dubious composition or low purity should be avoided.<br />

3.1. Fish collection and preservation<br />

Fish should preferably be manipulated and dissected just after their capture. If this is not possible fish<br />

should be frozen immediately after capture to prevent ionic exchanges between the plasma and the<br />

endolymph (internal fluid that fills the otosac and is in direct contact with the otolith). If immediate<br />

freezing is not possible, the fish can be kept refrigerated for a few hours before otolith removal (within<br />

the day). The use of formaldehyde or alcohol (even trace metal grade 100% ethanol) to preserve fish<br />

or fish heads must be avoided since it can alter otolith composition. The following procedure must be<br />

followed for otolith extraction in the laboratory (otolith dissection in the field is described at the end of<br />

this section).<br />

3.2. Otolith removal and preservation<br />

Disposable (powder free) polyethylene gloves must be worn at all times during otolith removal<br />

and subsequent handling. All the material to be in contact with either the otoliths or the solutions used<br />

to clean them (i.e. all dissecting tools and storage equipment) must be plastic, preferably Teflon,<br />

otherwise in high-density Polyethylene (HDPE) and need to be decontaminated prior to use.<br />

a) Procedure for material decontamination prior to use<br />

This procedure involves the use of a "Clean Cell" (i.e. class 10-horizontal laminar flow hood with<br />

its floor lined with polyethylene sheeting replaced periodically and wiped off before and after use with<br />

ultra-pure trace-metal grade ethanol). Only the material which has been decontaminated is referred to<br />

as "clean" in the present document. The decontamination procedure is as follows:<br />

1) Wash all equipment in 95% non-denatured ethanol.<br />

2) Rinse in ultra-pure (trace metal grade, 18.2 MΩ) water.<br />

3) Rest-wash (≥ 24 hours) in 4% nitric acid within HDPE buckets covered before and during<br />

immersion (acid bath = 0.2 L of 60% trace-metal grade HNO3 diluted with 2.8 L of ultra-pure<br />

water).<br />

4) Rinse 3 times with ultra-pure water.<br />

5) Rest-rinse (≥ 24 hours) in ultra-pure water within clean HDPE buckets covered before and<br />

during immersion.<br />

6) Air-dry for 12 h within the Clean Cell.<br />

7) Repackage in sealed clean plastic bags.<br />

INCO-CT-2006-026180 4 <strong>MUGIL</strong> Deliverable 4 - Feb. 2008


) Procedure for otolith extraction and preservation in the laboratory<br />

Use clean plastic (Teflon or HDPE) tools only to handle the otoliths and avoid metallic tools as<br />

much as possible during fish dissection. Wear gloves on both hands at all times (to manipulate the<br />

fish but also the dissecting instruments). All tools must be cleaned both before use and between<br />

each new dissection with 10% trace-metal grade nitric acid, then ultra-pure water. If the fish is<br />

frozen, it should be defrosted prior to otolith extraction. The fish dissection and otolith extraction<br />

protocol is as follows:<br />

1) Put an extra glove on the hand holding the fish, which will be removed after otolith extraction<br />

(i.e. when disposing the dissected fish).<br />

2) Hold the fish and make a frontal incision right above its eyes with a knife. For more detail<br />

regarding this section, refer to the Manual of Fish Sclerochronology (Panfili, 2002). NB: avoid<br />

scratching the otolith with the knife during this step.<br />

3) Using plastic forceps, crack the head open and remove fish’s brain.<br />

4) Once the otoliths are visible, use a second (clean) pair of plastic forceps to extract the otoliths.<br />

5) Place each otolith in a clean Petri dish filled with ultra-pure water (keep the Petri dish closed<br />

before use).<br />

6) Close the Petri dish, discard the fish and remove the extra glove on the hand holding the fish.<br />

7) Use the closed Petri dish for transporting the otoliths to view under a stereomicroscope.<br />

8) Using reflected light, clear the surface of each otolith of any adhering organic tissue using<br />

plastic forceps.<br />

9) Immerse the otolith for five minutes in a new clean microtube vial filled with 20% hydrogen<br />

peroxide (H2O2) (keep closed) to oxidise all remaining organic material from the otolith<br />

surface.<br />

10) Rinse the otolith in a new clean microtube vial filled with ultrapure water (keep closed).<br />

11) Once rinsed, place each otolith in a clean perfectly dry uniquely labelled plastic microtube<br />

vial (kept closed until this step).<br />

12) Close the microtube vial and reference it (fish identification number and indication of<br />

whether it is a LEFT or a RIGHT otolith). Left and right otoliths should be stored separately in<br />

different microtube vials since one could be used for microchemistry, and the other for age<br />

estimation. Information recorded for each referenced otolith should include the following: (i)<br />

unique reference number (engraved on the microtube vial), (ii) species, fish lengths (standard,<br />

fork and/or total) and mass, (iii) collection location (including GPS co-ordinates), (iv)<br />

collection method, and (v) collection date.<br />

13) Under the Clean Cell, open the microtube vials leaving the otoliths inside and allow drying for<br />

24 h under the ultra-clean conditions.<br />

14) Close the microtube vials containing individual otoliths and store them in the laboratory in<br />

sealed plastic bags until otolith processing. It is recommended to store only the otoliths from<br />

the same sampling station or sampling date in the same sealed plastic bags. Microtube vials<br />

containing LEFT and RIGHT otoliths should be stored in separate plastic bags to avoid<br />

unnecessary manipulation of vials since LEFT and RIGHT otoliths could have different uses.<br />

c) Notes on otolith extraction and preservation in field conditions<br />

Discussions during WS3 identified a number of cases where the above-mentioned ideal procedures<br />

(i.e. under clean laboratory conditions) would be impractical. These include: (i) when large numbers<br />

of fish are captured at a time, (ii) when dealing with exceptionally large fish, or (iii) when field trips<br />

last for more than a day and fish storage (freezing) capacity is limited. Under such conditions the<br />

following procedure is recommended from step 7:<br />

7) Place otoliths in a Petri dish and grossly clean the otolith surface of any adhering organic<br />

tissue, using plastic forceps.<br />

INCO-CT-2006-026180 5 <strong>MUGIL</strong> Deliverable 4 - Feb. 2008


8) Eventually sonify the otoliths in clean vials in ultrapure water during 3 to 5 minutes.<br />

9) Place each washed otolith in a clean uniquely labelled plastic microtube vial (perfectly dry<br />

and kept closed until this step).<br />

10) Close the microtube vial and reference it (fish identification number and indication of<br />

whether it is a LEFT or a RIGHT otolith). Left and right otoliths should be stored separately in<br />

different microtube vials since one can be used for microchemistry, and the other for age<br />

estimation.<br />

NB1: the otoliths will only be H2O2 cleaned and left to dry out (steps 9 to 14 of the lab procedure)<br />

once back at the laboratory.<br />

NB2: the otolith is a porous calcium carbonate structure. Its composition can be altered by<br />

incorporation of contaminating elements in fluids where the otolith is immersed, or tools with which<br />

the otolith surface is in contact, but also by leaking out of elements originally present in the otolith.<br />

For this reason it is important to avoid unnecessary manipulation of the otolith and extreme care<br />

during otolith manipulation should practised in these initial stages.<br />

3.3. Otolith preparation<br />

Otolith preparation is a required step to extract chemical information. Relevant microchemistry<br />

information can be acquired EITHER by analysing each otolith as a whole (thus obtaining a unique<br />

chemical signature for each individual corresponding to its complete life-time) OR by sampling<br />

discrete areas between age marks within the otolith (typically 5 to 50 μm-wide spots made on otolith<br />

transverse sections) that can be related to particular periods of the life of the fish. Before analysis, an<br />

image of the whole and/or sectioned otolith should be recorded but clearing media should be avoided<br />

(the only media should eventually be ultra-pure water).<br />

3.3.1. Otolith preparation: whole otolith<br />

The analysis of whole dissolved otoliths is the easiest, quickest and least contaminant way to<br />

extract chemical information from the otoliths. Unfortunately, this approach does not allow linking<br />

microchemistry variation to otolith age marks, unless the analysed individuals belong to the same age<br />

class and are captured at the same time. Therefore, the analysis should mainly be used to assess<br />

nursery area fingerprints from juvenile fish from different origins.<br />

The analysis of whole otoliths should be carried out individually. The first steps of this analysis<br />

should follow the protocol below:<br />

1) Weigh the otoliths individually with a 0.001 mg precision. Otolith weight needs to be<br />

accurately measured as elemental concentration is reported on a weight basis. Otolith<br />

weighing and manipulation should be carried out in ultra-clean conditions using dry plastic or<br />

Teflon forceps (previously cleaned with 10% nitric acid).<br />

2) Once weighed, each otolith should be transferred to individual plastic vials waiting for acid<br />

dissolution.<br />

3) Acid dissolution of the otolith should be carried out with ultra-pure nitric acid using a<br />

determined volume. Once dissolved the otolith solute is ready for analysis (See Section 3.4 on<br />

Otolith Chemical Analysis).<br />

INCO-CT-2006-026180 6 <strong>MUGIL</strong> Deliverable 4 - Feb. 2008


3.3.2. Otolith preparation: transverse sections<br />

Otolith transverse sections have already been identified during <strong>MUGIL</strong> WS2 as the most<br />

appropriate way of exposing internal growth marks in the otolith for age estimation. As such, chemical<br />

information to be related to these marks will be extracted from transverse sections.<br />

While detailed information on how to prepare otolith transverse sections for age estimation is<br />

available in <strong>MUGIL</strong> Deliverable 3 (<strong>Mugil</strong> life-history trait <strong>studies</strong>, October 2007), the preparation of<br />

otolith sections for microchemistry analysis requires additional precautions to avoid alteration of the<br />

original composition of the otolith. As for otolith dissection, the contact of the otolith with metallic<br />

tools should be avoided.<br />

a. Embedding<br />

The dried otolith is embedded in a transparent resin but polyester resins, as used for otolith<br />

preparation for age estimation, should be avoided as their composition might be a source of<br />

contaminating elements. Epoxy resins are preferred, among which Araldite seems a good compromise.<br />

The use of individually labelled moulds (e.g. made of silicon elastomer), dimensioned according to the<br />

otolith size is necessary. The below protocol should be followed:<br />

1) The resin and its catalyst are mixed thoroughly but taking care to prevent bubbles forming in<br />

the resin mixture. The process should only involve the use of plastic tools (vials, dishes,<br />

pipettes, even the stick used to mix the resin and the catalyst).<br />

2) The mixture is then left to rest for a few minutes to allow the biggest bubbles to reach the<br />

surface and disappear.<br />

3) The polyester resin is pipetted into the mould cell to create a base layer and allowed to harden<br />

for 24 h in an ultra clean dry oven (around 30-35 °C).<br />

4) The otolith is then placed in a mould cell and new resin (preparation as in 1)) is poured over<br />

the otolith until it is completely covered. At this step it is important to turn over the otolith in<br />

its mould to eliminate air bubbles that are often trapped below. After this, the otolith needs to<br />

be re-positioned before resin hardens.<br />

5) Re-positioning takes into account the next steps of preparation (e.g. the sectioning plane): the<br />

otolith is embedded with it anterior-posterior axis parallel to the main axis of the mould.<br />

6) The preparation is then set to harden for 24-48 h in a dry oven (30-35°C). The embedded<br />

otolith is then ready for sectioning.<br />

Note that any manipulation of the otolith, from the plastic vial where it is stored to the mould,<br />

even when immersed in the resin before it hardens, has to be done with plastic or Teflon forceps. The<br />

resulting resin block should not be manipulated with bare hands, always use clean gloves to remove it<br />

from the mould. If the block is not to be cut right after embedding, it should be stored in sealed plastic<br />

bags in the same manner as the microtube vials containing freshly extracted otoliths.<br />

b. Transverse sectioning<br />

The sectioning reveals the internal otolith increments. While being a necessary step it also<br />

represents a critical stage at which the internal structure of the otolith is exposed to fluids and<br />

suspensions. Extra care has to be taken to follow a standard procedure. Sectioning is done using a lowspeed<br />

circular saw (e.g. Isomet® saw, Buehler Ltd) equipped with a diamond blade. The cooling fluid<br />

used has to be ultrapure MilliQ water. Usually the recipient used for the cooling liquid is made of bare<br />

metal. While one possibility is to find a container of similar dimensions made of plastic, it is also<br />

possible to place a smaller container made of plastic inside the main metallic container. This avoids<br />

any contact between the cooling fluid and the metal and thus between the blade and subsequently the<br />

otolith internal structure. As in the previous stage, always manipulate the resin block using clean<br />

gloves. It is not possible to replace the metallic arm of the saw, the metallic resin block holder or the<br />

metallic instruments to tighten the block to the holder by non metallic substitutes. Thus care has to be<br />

INCO-CT-2006-026180 7 <strong>MUGIL</strong> Deliverable 4 - Feb. 2008


taken to avoid unnecessary friction between these and the resin block. The next steps of the procedure<br />

should follow the protocol below:<br />

1) Fill the water container of the saw with ultrapure MilliQ water.<br />

2) Fix the resin block including the otolith to the saw holder. After this step no further<br />

manipulation of the block is required.<br />

3) Adjust the section levels with the saw micrometer. Work to obtain sections with a maximum<br />

500 μm if the otolith is to be sampled by Laser Ablation and a maximum of 300 μm if the<br />

otolith surface is to be analysed with an electron probe (See Section 3.3 on Chemical<br />

Analysis).<br />

4) Align the diamond blade at the level of the otolith core.<br />

5) Move the diamond blade with the saw micrometer at a distance of half of the required section<br />

thickness. Section the resin block.<br />

6) Move the diamond blade with the saw micrometer in the opposite direction at a distance of the<br />

required section thickness. Section the resin block. The resulting section will be detached from<br />

the resin block at the end of the second section. Avoid having the section falling down into the<br />

recipient containing the cooling fluid. Hold it with thin plastic or Teflon forceps and remove it<br />

from the sectioning set to a Petri dish to be rinsed with MilliQ water.<br />

7) Place inside the section into a microtube vial and leave to dry.<br />

8) Return to the sectioning set, remove the resin block and thoroughly rinse the blade with<br />

ultrapure MilliQ water.<br />

9) Dispose the water from the saw container, rinse thoroughly and fill again with fresh ultrapure<br />

MilliQ water, ready for the next otolith.<br />

c. Section manipulation<br />

If the dry otolith section cannot be further manipulated without being affixed to a solid support,<br />

due for example to its small size, the section should be attached to a clean glass slide (preferably of the<br />

geological type rather than the histological type). Use Araldite resin to mount the section onto the<br />

centre of the glass slide and manipulate the section with plastic or Teflon forceps. The glass slide<br />

should not be manipulated without clean gloves.<br />

d. Surface polishing<br />

Growth marks will be best observed in a plane that includes the core. Since the objective of<br />

sectioning is only to grossly expose the internal structure of the otolith, grinding and polishing are<br />

necessary to reach the plane of the core. Some degree of experience is necessary to make thin sections<br />

of otoliths. Otolith preparation for microchemistry analysis should be attempted after the user is<br />

familiarised with the preparation of thin sections for age estimation.<br />

Grinding should use clean abrasive papers wetted with ultrapure MilliQ water only. In all cases<br />

the use of an automatic polishing machine should be regarded as highly desirable since it will ensure a<br />

standard grinding and polishing of preparations.<br />

1- Use gloves to manipulate abrasive papers between the site of storage (this must be a dust free<br />

holder in closed cupboards) and the polishing machine.<br />

2- Place the abrasive paper in the polishing machine.<br />

3- Attach the otolith section mounted on a geological glass slide to the specimen holder of the<br />

polishing machine.<br />

4- Place the specimen holder on the abrasive paper and under the arm of the polishing machine.<br />

5- Wet the abrasive paper with ultrapure MilliQ water.<br />

6- Start the grinding process.<br />

7- Check regularly the level of grinding under a binocular microscope. To do so, it will be<br />

necessary to slightly polish the otolith surface to remove scratches left by the grinding. To do<br />

so, proceed as follows:<br />

8- Remove the specimen holder with the otolith from the polishing machine.<br />

9- Clean in an ultrasonic bath with ultrapure MilliQ water.<br />

INCO-CT-2006-026180 8 <strong>MUGIL</strong> Deliverable 4 - Feb. 2008


10- Rinse the holder with the otolith with ultrapure MilliQ water.<br />

11- Polish the otolith against a polishing cloth with a 3 microns water based diamond suspension<br />

(the manipulation of polishing cloths are the same as for abrasive papers, as described in 1)).<br />

12- Rinse the holder with the otolith with ultrapure MilliQ water.<br />

13- Place the specimen holder with the otolith under a binocular microscope and check the level<br />

of polishing. If the plane of the core is not near the otolith surface, move to steps (9), (10) and<br />

from (2) to (13) until reaching the plane of the core.<br />

14- Once finished, remove the glass slide with the otolith from the specimen holder.<br />

15- Clean it in an ultrasonic bath with ultrapure MilliQ water during 1-3 minutes.<br />

16- Place it in a clean plastic slide box (kept closed until then to avoid dust) and leave to dry<br />

under the Clean Cell and allow drying for 24 h under the ultra-clean conditions.<br />

17- Clean the specimen holder of the polishing machine with ultrapure MilliQ water.<br />

18- Rinse thoroughly the abrasive paper of the polishing machine with ultrapure MilliQ water. To<br />

insure less contamination the abrasive paper should be changed between otoliths.<br />

19- Proceed to the grinding of the next otolith.<br />

If samples are to be analysed with electron probes the surface of the otolith section needs to be<br />

perfectly flat and free of scratches. Thus, final polishing has to be taken to the finest grains of<br />

polishing (1 μm to 0.25 μm) to ensure the removal of scratches. Always check the quality of the<br />

preparation under an epi-illumination compound microscope at high magnification. If samples are to<br />

be analysed with LA-ICPMS, the quality of the preparation is less relevant and a polishing with 3 to<br />

1 μm should be enough. In all cases, polishing suspensions should be water based diamond<br />

suspensions (alumina powders should be avoided). For polishing, proceed as follows:<br />

20- Use gloves to manipulate the polishing cloth between the site of storage (this must be a dust<br />

free holder kept in closed cupboards) and the polishing machine.<br />

21- Place the polishing cloth in the polishing machine.<br />

22- Attach the otolith section mounted on a geological glass slide to the specimen holder of the<br />

polishing machine.<br />

23- Place the specimen holder on the polishing cloth and under the arm of the polishing machine.<br />

24- Wet the polishing cloth with a 3 µm water based diamond suspension.<br />

25- Start the polishing process.<br />

26- Check regularly the progress of the polishing process under a compound microscope with epiillumination.<br />

At this stage, it is a matter of assessing whether scratches disappear from the<br />

otolith surface. To do so, proceed as follows:<br />

27- Remove the specimen holder with the otolith from the polishing machine.<br />

28- Clean in an ultrasonic bath with ultrapure MilliQ water during few seconds.<br />

29- Rinse the holder with the otolith with ultrapure MilliQ water.<br />

30- Place the glass slide with the otolith under a compound microscope with epi-illumination at<br />

×50 magnification and check the progress of the polishing. If more polishing with the 3 µm<br />

suspension is required, move to steps (28), (29) and from (23) to (26) until the quality of the<br />

surface is satisfactory across the surface of the sample.<br />

31- Once finished, remove the glass slide with the otolith from the specimen holder.<br />

32- Clean it in an ultrasonic bath with ultrapure MilliQ water during 1-3 minutes.<br />

33- Place it in clean plastic slide box and leave to dry under the Clean Cell and allow drying for<br />

24 h under the ultra-clean conditions.<br />

34- Clean the specimen holder of the polishing machine with ultrapure MilliQ water. Change the<br />

polishing cloth to avoid contamination.<br />

35- Proceed to the polishing of the next otolith.<br />

The same sequence of steps from (20) to (35) will be followed using 1 µm water diamond<br />

suspensions. An additional sequence of polishing with a 0.25 µm water diamond suspension will be<br />

done if the otolith surface is to be analysed with WDS.<br />

INCO-CT-2006-026180 9 <strong>MUGIL</strong> Deliverable 4 - Feb. 2008


e. Final cleaning<br />

After the polishing stage, the preparation should be cleaned in an ultrasonic bath with MilliQ<br />

water during 1-3 minutes. Place it in a clean plastic slide box (kept closed until then to avoid dust) and<br />

leave to dry under the Clean Cell for 24 h under the ultra-clean conditions.<br />

f. Image acquisition<br />

The otolith increments on the transverse sections are to be examined under transmitted light. It is<br />

recommended that digital images of the otolith sections are captured showing relevant parts of the<br />

otolith, i.e. core, growth marks along the axis of analysis and otolith edge as these will ease locating<br />

the zone of the otolith to be analysed once the otolith is inside the analytical instrument.<br />

3.4. Otolith chemical analysis<br />

The chemical analysis of the otolith seeks extracting information on elements or isotopes through<br />

screening and quantification of concentrations from the otolith mineral and organic matrix. It is<br />

possible to extract information from the whole otolith by sampling the solution resulting from<br />

dissolving the whole otolith OR by sampling the otolith at discrete spots using high resolution electron<br />

probes OR using laser ablation which is the more powerful technique. The choice of instruments to be<br />

used within <strong>MUGIL</strong> was decided during WS3 and selected instruments were chosen among several<br />

candidates listed in the literature (EDS, ICPMS, SIMS, AAS, AES…). All these approaches have<br />

advantages and disadvantages which are outlined below.<br />

3.4.1. Whole otolith analysis: SB-ICPMS<br />

Dissolving and quantifying elements in the whole otolith will provide information about the<br />

concentrations of elements over the entire life of the fish. Since this approach does not require more<br />

preparation than dissolving the otolith in nitric acid, otolith composition is probably maintained. Yet,<br />

this approach will render data of limited use to study fish <strong>migration</strong>: while it would probably help<br />

discriminating migrating fish from non-migrating fish, it will not help to distinguish a fish that<br />

commutes every season from seawater to freshwater from a fish that has spent half of its life in<br />

freshwater and the other half at sea. Yet, it can be regarded as an interesting approach to make<br />

estimations about the fraction of a sample/population that is freshwater resident, seawater resident or<br />

migrant.<br />

The selected instrument to be used within <strong>MUGIL</strong> is an Inductively Coupled Plasma Mass<br />

Spectrometer (ICPMS) sampling in continuous mode the solution containing the dissolved otolith. The<br />

solution is pumped towards the plasma torch which ionises the sampled matrix. Ionised elements are<br />

accelerated through cones to align and sub-sample the ionised cloud. Magnets and mass acceleration<br />

serve to filter masses of elements which are sequentially projected to a Faraday cup or electron<br />

multiplier for quantification. Counts are then related to concentrations by use of standards analysed at<br />

increasing concentrations. Internal standards should be quantified over any session of analysis to<br />

quantify instrument drift. Samples should be analysed in random sequences. Interferences between<br />

molecules of same mass and particularly those containing the ubiquitous oxygen or calcium should be<br />

checked (instruments these days include lists of interfering signals and have also increased their mass<br />

resolution).<br />

The advantages of this instrument are i) the low limits of detection that allow quantifying isotopes<br />

at the ppb level (part per billion), ii) the fact that this type of instrument is increasingly common in<br />

INCO-CT-2006-026180 10 <strong>MUGIL</strong> Deliverable 4 - Feb. 2008


geological labs and universities, and iii) the possibility of processing a large number of samples for<br />

which a large number of elements or isotopes can be quantified at the same time.<br />

Fish <strong>migration</strong> will definitely be best studied by analysing the variation of concentrations of the<br />

elements selected as tracers of salinity changes (usually Sr and Ca) in relation to age marks in the<br />

otolith. This implies sampling only the surface of the otolith at discrete spots. The required size of<br />

these spots, the number and expected concentrations of the elements to be measured and the cost of<br />

analysis will determine the use of an electron probe (WDS) or a laser ablation ICPMS instrument.<br />

3.4.2. Surface analysis: electron probes WDS<br />

Low costs and easy-access are the main reasons to choose an electron probe to analyse Sr and Ca<br />

in fish otoliths. The selected type of electron probe to be used within <strong>MUGIL</strong> is a Wavelength<br />

Dispersive Spectrometer (WDS) which has the advantage of separating the functions of detection and<br />

quantification as opposed to other types of electron probes. Analysis is based on the detection and<br />

quantification of X-Rays emitted from a discrete zone of the otolith surface excited by a beam of<br />

primary electrons accelerated from a tungsten filament located above the sample. To improve the<br />

quality of analysis the otolith surface should be previously coated with a thin layer of carbon to<br />

remove electrons accelerated to the sample. Beam current, accelerating voltage and spot size should be<br />

standardised to 10 nA, 15 keV and 10 μm within <strong>MUGIL</strong> consortium. Counting times at peak should<br />

be 30 sec for Ca and 90 sec for Sr and half in the background (only one side).<br />

3.4.3. Surface analysis: LA-ICPMS<br />

Otoliths will be best screened for elements with Laser Ablation Inductively Coupled Mass<br />

Spectrometry (LA-ICPMS) when the elements to quantify are more than Ca and Sr. For instance,<br />

alternative elements such as Ba may constitute good tracers of estuarine environments. To do this, the<br />

otolith section is introduced in the sealed laser chamber coupled to an ICPMS instrument. A CCD<br />

camera inside the chamber allows visualisation of the otolith surface and selecting the exact location<br />

to be hit by the laser from a monitor. Firing the laser at the otolith surface will result in the ablation of<br />

otolith portions that will be left in suspension over the otolith. An Argon gas flow transports any<br />

vaporised matter ablated towards the plasma torch within the ICPMS where the ionised elements are<br />

filtered, aligned and quantified (See Section 3.4.1.Whole otolith analysis: SB-ICPMS). Sizes of the<br />

ablated spots vary between 50 down to 5 μm. Any element present in these vaporised portions of the<br />

otolith surface whose concentration which is above the limit of detection of the instrument can be<br />

measured in the same manner described above in Section 3.4.1. (Whole otolith analysis: SB-ICPMS)<br />

taking advantage of the capabilities of the ICPMS.<br />

3.5. Data treatments for otolith microchemistry<br />

The extraction of data of chemical composition through surface analysis pursues the<br />

characterisation of elemental variations across the otolith, usually between the otolith core (formed at<br />

hatching) and the otolith edge (formed just before capture).<br />

INCO-CT-2006-026180 11 <strong>MUGIL</strong> Deliverable 4 - Feb. 2008


The standards to be used by each laboratory should be the same. If different glass standards are<br />

used with LA-ICPMS instruments, an inter-calibration exercise should be run before running<br />

extensive analyses between the laboratories implicated.<br />

The typical output of data is presented in Table 1 and can be imported as a spreadsheet where lines<br />

represent the information relative to each isotope (Ca 44 , Sr 88 for example) and columns list each<br />

sample, standards or blanks.<br />

Data in CPS (counts per second) are transformed through the calibration curves from the standards<br />

into concentrations in ppm (parts per million) or ppb (parts per billion). Depending on the number of<br />

samples to be treated, it may be necessary to use internal standards to assess for instrumental drift<br />

along the day, for example by alternating the analysis of otoliths and standards. Raw data should be<br />

inspected first to assess instrument drift.<br />

Raw data have to be treated before being used. To do so, follow the following protocol:<br />

1. Identify in the columns which are standards, internal standards and samples.<br />

2. Look for raw data with background subtracted (clean raw data).<br />

3. Look for MDL (Minimum Detection Limits) data that represent the threshold below which<br />

the instrument cannot distinguish between concentrations and noise. Note that these are<br />

generally reported in ppm or ppb.<br />

4. Look for clean raw data in the ppm or ppb form (not CPS) not filtered for MDL.<br />

5. Verify that for each analysis and isotope, concentrations are above the MDL. The instrument<br />

software may do this automatically. Any data below MDL should be discarded. The resulting<br />

data is MDL filtered and can be used for posterior data treatment.<br />

Table 1. LA-ICPMS data output of chemical composition: isotopes of calcium (Ca), strontium (Sr) and barium (Ba).<br />

GLITTER4.0: Laser Ablation Analysis Results<br />

E:\LA-DATA\JacquesPanfili\mmh403profil\MMH403profil.FIN<br />

Mon Jan 21 10:21:07 2008<br />

All values are reported in ppm<br />

GLITTER!: Trace Element Concentrations MDL filtered.<br />

Element DCSTD_11 MMH403profil_1 MMH403profil_2MMH403profil_3 MMH403profil_4 MMH403profil_5 DCSTD_12<br />

Ca43 81833,28 400232,66 400232,59 400232,63 400232,59 400232,63 81833,28<br />

Ca44 82162,27 406706,06 411860,66 408979,72 409102 410456,66 81807,77<br />

Sr88 499,63 3447,93 2042,35 1515,89 2321,84 2202,8 496,31<br />

Ba138 425,18 6,89 2,904 5,65 13,19 12,75 423,41<br />

GLITTER!: Trac Not filtered for MDL.<br />

Element DCSTD_11 MMH403profil_1 MMH403profil_2MMH403profil_3 MMH403profil_4 MMH403profil_5 DCSTD_12<br />

Ca43 81833,28 400232,66 400232,59 400232,63 400232,59 400232,63 81833,28<br />

Ca44 82162,27 406706,06 411860,66 408979,72 409102 410456,66 81807,77<br />

Sr88 499,63 3447,93 2042,35 1515,89 2321,84 2202,8 496,31<br />

Ba138 425,18 6,89 2,904 5,65 13,19 12,75 423,41<br />

GLITTER!: 1 sigma error.<br />

Element DCSTD_11 MMH403profil_1 MMH403profil_2MMH403profil_3 MMH403profil_4 MMH403profil_5 DCSTD_12<br />

Ca43 2630,77 12692,09 12690,12 12689,5 12689,15 12692,33 2629,86<br />

Ca44 2620,54 12876,02 13038,11 12946,58 12950,26 12994,88 2608,74<br />

Sr88 15,34 105,02 62,21 46,18 70,72 67,1 15,24<br />

Ba138 12,97 0,22 0,1 0,18 0,41 0,4 12,92<br />

GLITTER!: Minimum detection limits (99% confidence).<br />

Element DCSTD_11 MMH403profil_1 MMH403profil_2MMH403profil_3 MMH403profil_4 MMH403profil_5 DCSTD_12<br />

Ca43 282,65 231,63 219,19 226,68 213,67 219,31 256,4<br />

Ca44 101,55 85,52 81,24 83,98 79,76 84,45 95,11<br />

Sr88 0,178 0,143 0,148 0,148 0,149 0,155 0,173<br />

Ba138 0,0616 0,05 0,048 0,05 0,0448 0,0456 0,0559<br />

GLITTER!: Mean Raw CPS background NOT subtracted.<br />

Element DCSTD_11 MMH403profil_1 MMH403profil_2MMH403profil_3 MMH403profil_4 MMH403profil_5 DCSTD_12<br />

Ca43 179858 958731 1013360 1007298 1042919 1002256 184573<br />

Ca44 2830746 14773582 15805902 15605130 16160239 15591435 2894563<br />

Sr88 1042617 8113390 5084012 3751397 5948820 5425059 1068471<br />

Ba138 976801 18507 8601 16066 37884 35195 1003332<br />

GLITTER!: Mean Raw CPS background subtracted.<br />

Element DCSTD_11 MMH403profil_1 MMH403profil_2MMH403profil_3 MMH403profil_4 MMH403profil_5 DCSTD_12<br />

Ca43 171853 951553 1006173 1000009 1035684 995495 177271<br />

Ca44 2596698 14551988 15582310 15378525 15931904 15364383 2667015<br />

Sr88 1037971 8109365 5079231 3746864 5943681 5420118 1063571<br />

Ba138 976119 17908 7982 15429 37313 34671 1002709<br />

INCO-CT-2006-026180 12 <strong>MUGIL</strong> Deliverable 4 - Feb. 2008


4. General conclusions and recommendations<br />

Following <strong>MUGIL</strong> WS3 the consortium has defined guidelines for the application of otolith<br />

microchemistry to study <strong>migration</strong> and dispersal across saline gradients by <strong>Mugil</strong> cephalus and<br />

proposes a standard protocol for otolith dissection, manipulation, storage, preparation and analysis.<br />

For transhaline <strong>migration</strong> <strong>studies</strong> of M. cephalus the <strong>MUGIL</strong> consortium recommends the<br />

chemical analysis of transverse sections of otoliths. Sections should be preferentially analysed with<br />

LA-ICPMS along the axis of the otolith with visible and interpretable growth marks.<br />

Extreme care should be put in manipulating otoliths and avoiding excessive manipulation, the<br />

contact with any metallic tool, bare hands or immersion or rinsing with solutions of unknown<br />

composition and low purity. As such, otoliths should only be rinsed in ultrapure MilliQ water and<br />

cleaned in pure hydrogen peroxide (H2O2). Otoliths can only be stored dry and clean of any organic<br />

remains in individual microtube vials in clean sealed plastic bags. While it is acknowledged that it is<br />

not feasible to avoid altering to some extent the composition of the otolith by manipulation and<br />

preparation, it is stressed that the strict use of this standard protocol will reduce the sources of error.<br />

Otolith analysis should be done with LA-ICPMS (for multi-elemental screening) or WDS (for Sr<br />

and Ca). It is acknowledged that Sr and Ca are to date the best candidates to track transhaline<br />

<strong>migration</strong>s of individual fish, yet the possibility exists that other elements may bring additional<br />

information to identify fish dispersal within freshwater using strontium isotopes or to identify fidelity<br />

to certain coastal areas using Mn, Ni, Zn and Ba. Since LA-ICPMS is superior to WDS in multielemental<br />

screening and sensibility, the former should be used with otoliths.<br />

Otolith microchemistry has drawn much attention in recent years and the number of publications<br />

reporting results on the application of otolith microchemistry to study diadromous fish transhaline<br />

<strong>migration</strong>s has increased significantly. Yet more and more evidence is available regarding the<br />

necessity of validating the relationship between otolith chemical information and environmental<br />

information. Therefore, the <strong>MUGIL</strong> consortium recommends the conducting of validation experiments<br />

in controlled rearing conditions before applying the technique. Experimental designs will bring the<br />

possibility of working out coefficients of discrimination of relevant elements between the water and<br />

the otolith for fish of different ages/sizes in at least two zones covered by <strong>MUGIL</strong>. Validation<br />

experiments will allow for a wide application of the technique based on a sound methodology.<br />

5. References<br />

Arai, T., Hirata, T., & Takagi, Y. (2007). Application of laser ablation ICPMS to trace the<br />

environmental history of chum salmon Oncorhynchus keta. Marine Environmental Research<br />

63 (1), 55-66.<br />

Bacheler, N. M., Wong, R. A., & Buckel, J. A. (2005). Movements and mortality rates of stripped<br />

mullet in North Carolina. North American Journal of Fisheries Management 25 (1), 361-373.<br />

Campana, S. E. (1999). Chemistry and composition of fish otoliths: pathways, mechanisms and<br />

applications. Marine Ecology Progress Series 188, 263-297.<br />

INCO-CT-2006-026180 13 <strong>MUGIL</strong> Deliverable 4 - Feb. 2008


Campana, S. E., Thorrold, S. R., Jones, C. M., Gunther, D., Tubrett, M., Longerich, H., Jackson, S.,<br />

Halden, N. M., Kalish, J. M., Piccoli, P., de Pontual, H., Troadec, H., Panfili, J., Secor, D. H.,<br />

Severin, K. P., Sie, S. H., Thresher, R., Teesdale, W. J., & Campbell, J. L. (1997).<br />

Comparison of accuracy, precision and sensitivity in elemental assays of fish otoliths using the<br />

electron microprobe, proton-induced X-ray emission, and laser ablation inductively coupled<br />

plasma mass spectrometry. Canadian Journal of Fisheries and Aquatic Sciences 54, 2068-<br />

2079.<br />

Chang, C. W., Iizuka, Y., & Tzeng, W. N. (2004a). Migratory environmental history of the grey<br />

mullet <strong>Mugil</strong> cephalus as revealed by otolith Sr:Ca ratios. Marine Ecology Progress Series<br />

267, 277-288.<br />

Chang, C. W., Lin, S. H., Iizuka, Y., & Tzeng, W. N. (2004b). Relationship between Sr:Ca ratios in<br />

otoliths of grey mullet <strong>Mugil</strong> cephalus and ambient salinity: validation, mechanisms, and<br />

applications. Zoological Studies 43 (1), 74-85.<br />

Daverat, F., Tomás, J., Lahaye, M., Palmer, M., & Elie, P. (2005). Tracking continental habitat shifts<br />

of eels using otolith Sr/Ca ratios: validation and application to the coastal, estuarine and<br />

riverine eels of the Gironde-Garonne-Dordogne watershed. Marine and Freshwater Research<br />

56, 619-627.<br />

Jessop, B. M., Shiao, J. C., Iizuka, Y., & Tzeng, W. N. (2002). Migratory behaviour and habitat use by<br />

American eels Anguilla rostrata as revealed by otolith microchemistry. Marine Ecology<br />

Progress Series 233, 217-229.<br />

Kalish, J. M. (1990). Use of otolith microchemistry to distinguish the progeny of sympatric<br />

anadromous and non-anadromous salmonids. Fishery Bulletin 88 (4), 657-666.<br />

Panfili, J. (2002). Extraction and conservation of calcified structures. In Manual of Fish<br />

Sclerochronology (Panfili, J., de Pontual, H., Troadec, H., and Wright, P. J., eds.), pp. 317-<br />

330. Brest, France: Ifremer-IRD coedition.<br />

Thomson, J. M. (1955). The movements and <strong>migration</strong>s of mullet (<strong>Mugil</strong> cephalus L.). Australian<br />

Journal of Marine and Freshwater Research 2, 328-347.<br />

Thorrold, S. R., Jones, C. M., Campana, S. E., McLaren, J. W., & Lam, J. W. H. (1998). Trace<br />

element signatures in otoliths record natal river of juvenile American shad (Alosa<br />

sapidissima). Limnology and Oceanography 43 (8), 1826-1835.<br />

Tomás, J., Augagneur, S., & Rochard, E. (2005). Discrimination of the natal origin of juvenile allis<br />

shad (Alosa alosa) in the Garonne - Dordogne basin (south-west France) using otolith<br />

chemistry. Ecology of Freshwater Fish 14, 185-190.<br />

Tzeng, W. N., Shiao, J. C., & Iizuka, Y. (2003). Use of otolith Sr:Ca ratios to study the riverine<br />

migratory behaviors of Japanese eel Anguilla japonica. Marine Ecology Progress Series 245,<br />

213-221.<br />

Volk, E. C., Blakley, A., Schroder, S. L., & Kuehner, S. (2000). Otolith chemistry reflects migratory<br />

characteristics of Pacific salmonids: Using otolith core chemistry to distinguish maternal<br />

associations with sea and freshwaters. Fisheries Research 46 (1-3), 251-266.<br />

Wang, C. H., Tzeng, W. N., & You, C. F. (2006). Geographic variation of otolith elemental<br />

composition in the juvenile grey mullet (<strong>Mugil</strong> cephalus) collected from Taiwanese estuaries.<br />

In press ,<br />

INCO-CT-2006-026180 14 <strong>MUGIL</strong> Deliverable 4 - Feb. 2008


6. Author addresses<br />

J. Tomás<br />

K. Anastasopoulou<br />

P. Berrebi<br />

P.D. Cowley<br />

A. Darnaude<br />

P. S. Diouf<br />

J.-D. Durand<br />

Postal: IRD - UR 070, UMR 5119, Laboratoire ECOLAG, <strong>Université</strong> <strong>Montpellier</strong> 2,<br />

cc 093, Place E. Bataillon, 34095 <strong>Montpellier</strong> Cedex 5, France<br />

Email javier.tomas@mac.com<br />

Postal: Hellenic Centre for Marine Research, Institute of Marine Biological<br />

Resources, Aghios Kosmas, 167 77 Hellinikon, Athens, Greece<br />

Email kanast@ath.hcmr.gr<br />

Postal: UMR 5554 Institut des Sciences de l'Evolution, Equipe Génétique et<br />

Environnement / Métapopulations, Conservation et Co-évolution <strong>Université</strong><br />

<strong>Montpellier</strong> II, CC 065. Place E. Bataillon 34095 <strong>Montpellier</strong> Cedex 5, France<br />

Email berrebi@univ-montp2.fr<br />

Postal: South African Institute for Aquatic Biodiversity, Private Bag 1015,<br />

Grahamstown, 6140, South Africa<br />

Email p.cowley@ru.ac.za<br />

Postal: IRD - UR 070, UMR 5119, Laboratoire ECOLAG, <strong>Université</strong> <strong>Montpellier</strong> 2,<br />

cc 093, Place E. Bataillon, 34095 <strong>Montpellier</strong> Cedex 5, France<br />

Email audrey.darnaude@univ-montp2.fr<br />

Postal: WWF WAMER, Sacré Coeur 3, n° 9442, Dakar, Senegal<br />

Email psdiouf@wwfsenegal.org<br />

Postal: IRD UR 070 RAP, Route des Hydrocarbures, BP 1386 Bel Air, Dakar,<br />

Senegal<br />

Email Jean-Dominique.Durand@ird.sn<br />

D. Flores-Hernandez Postal: Centro EPOMEX, Universidad Autónoma de Campeche, Av. Agustín Melgar<br />

y Juan de la Barrera, Apdo. Postal 520, 24030 Campeche, Mexico<br />

Email doflores@mail.uacam.mx<br />

B. Morales-Nin<br />

W.N. Tzeng<br />

C.-H. Wang<br />

A.K. Whitfield<br />

J. Panfili<br />

Postal: Instituto Mediterráneo Estudios Avanzados (CSIC/UIB),<br />

Miguel Marqués 21, 07190 Esporles, Islas Baleares, Spain<br />

Email ieabmn@uib.es<br />

Postal: Institute of Fisheries Science, National Taiwan University, No. 1, Sec. 4,<br />

Roosevelt Road, Taipei, 10617 Taiwan, Republic of China<br />

Email wnt@ntu.edu.tw<br />

Postal: Institute of Fisheries Science, National Taiwan University, No. 1, Sec. 4,<br />

Roosevelt Road, Taipei, 10617 Taiwan, Republic of China<br />

Email chwang@mail.ncku.edu.tw<br />

Postal: SAIAB, Private Bag 1015, Grahamstown 6140, South Africa<br />

Email A.Whitfield@ru.ac.za<br />

Postal: IRD - UR 070, UMR 5119, Laboratoire ECOLAG, <strong>Université</strong> <strong>Montpellier</strong> 2,<br />

cc 093, Place E. Bataillon, 34095 <strong>Montpellier</strong> Cedex 5, France<br />

Email panfili@ird.fr<br />

INCO-CT-2006-026180 15 <strong>MUGIL</strong> Deliverable 4 - Feb. 2008


7. Annexure 1 – WS3 Agenda<br />

WORKSHOP 3<br />

<strong>MUGIL</strong><br />

Main Uses of the Grey mullet as Indicator of<br />

Littoral environmental changes<br />

2006 - 2009<br />

Agenda<br />

26 - 28 September 2007<br />

INCO-CT-2006-026180 <strong>MUGIL</strong> Deliverable 4 – Feb. 2008


Homepage:<br />

www.mugil.univ-montp2.fr<br />

Coordinator:<br />

J. Panfili (IRD)<br />

Contents<br />

WORKSHOP 3<br />

<strong>MUGIL</strong><br />

Main Uses of the Grey mullet as Indicator<br />

of Littoral environmental changes<br />

2006 - 2009<br />

26 - 28 September 2007<br />

Objectives<br />

<strong>MUGIL</strong> will elaborate guidelines for <strong>migration</strong><br />

<strong>studies</strong> (otolith microchemistry, fishery data,<br />

genetics, telemetry). All participants will be<br />

compelled to using the same protocols.<br />

European<br />

Commission<br />

INCO-CT-2006-026180<br />

<strong>MUGIL</strong><br />

Page<br />

1. OBJECTIVES OF <strong>MUGIL</strong> WS3 ON MIGRATION ······················································································ 2<br />

2. AGENDA······················································································································································· 2<br />

3. LIST OF PARTICIPANTS····························································································································· 5


1. Objectives of <strong>MUGIL</strong> WS3 on <strong>migration</strong><br />

Dear <strong>MUGIL</strong> colleagues,<br />

The third <strong>MUGIL</strong> Workshop (WS3), related to <strong>Mugil</strong> <strong>migration</strong> <strong>studies</strong>, will be held at the<br />

ECOLAG laboratory (<strong>Montpellier</strong> 2 University) in <strong>Montpellier</strong>, France, 26-28 September 2007<br />

(host: Jacques Panfili). As you all know, this WS3 was initially scheduled to be hosted by<br />

IMEDEA in Palma de Mallorca, Spain. This change of host responds to unexpected logistic<br />

problems at IMEDEA. Nonetheless, we have ensured, in coordination with IMEDEA, that the<br />

change of host will not in any way compromise the success of this WS.<br />

WS3 will be focused on the topic of <strong>migration</strong>, and more precisely on approaches to follow<br />

individual movements of mugilids. The objective of studying <strong>migration</strong> within <strong>MUGIL</strong> is to<br />

assess the differences between ontogenetic <strong>migration</strong>s and <strong>migration</strong>s caused by other<br />

factors (environmental conditions, anthropogenic causes). It will start with a synthesis on<br />

current and past results obtained in research <strong>studies</strong> on different fields of interest: otolith<br />

microchemistry, telemetry, genetics and fishery data. WS3 will more precisely focus on the<br />

application of otolith microchemistry to study <strong>Mugil</strong> cephalus <strong>migration</strong>s. WS3 will thus be<br />

dedicated to agree on a standard protocol for otolith dissection, preparation and processing<br />

for bulk and surface analysis as well as on data treatment. The synthesis and personal<br />

experiences will give the basis to decide on one eligible method of processing and analysis.<br />

Finally, WS3 will provide a deliverable permitting to choose a standard protocol for otolith<br />

processing as well as methods, instruments and recommendations on the use of these tools.<br />

At the end <strong>MUGIL</strong> will elaborate guidelines for <strong>migration</strong> <strong>studies</strong> and at least all participants<br />

will be compelled to using the same protocols.<br />

This meeting will also be the occasion to start discussions on the preparation of a new<br />

proposal to be submitted to the EU:<br />

We are looking forward to seeing you in <strong>Montpellier</strong>.<br />

Yours sincerely,<br />

Javier Tomás & Jacques Panfili<br />

2. Agenda<br />

Wednesday 26 September 2007 – Overview of available methods<br />

9h - 10h00<br />

- M. Troussellier (director of ECOLAG laboratory, UM2). Welcome.<br />

- J. Panfili. Information on <strong>MUGIL</strong> WS3 accommodation.<br />

- Update of <strong>MUGIL</strong> internet web-pages.<br />

10h00 - 10h30<br />

- J.-D. Durand / P. Berrebi. Application of genetic markers to the study of <strong>Mugil</strong><br />

cephalus <strong>migration</strong>.<br />

10h30 - 10h45<br />

Coffee break


10h45 - 12h30<br />

- P. Cowley. The use of telemetry in <strong>studies</strong> of <strong>Mugil</strong> cephalus <strong>migration</strong>. Insights into<br />

technology and methods.<br />

- J. Tomás. Otolith microchemistry: principles and application to the analysis of fish<br />

<strong>migration</strong>.<br />

- J. Tomás. Instruments available in otolith microchemistry. Which method for which<br />

approach?<br />

12h30 - 14h00<br />

LUNCH at <strong>Montpellier</strong> 2 University<br />

14h00 - 16h00<br />

- C.-H. Wang. Application of otolith microchemistry to the study of <strong>Mugil</strong> cephalus<br />

<strong>migration</strong> in Taiwanese waters.<br />

- A. Darnaude. Application of otolith microchemistry to the study of <strong>Mugil</strong> cephalus<br />

<strong>migration</strong> in Corsica waters (Mediterranean Sea).<br />

- W.-N. Tzeng. <strong>Mugil</strong> cephalus <strong>migration</strong> around Taiwanese waters assessed through<br />

fishery data.<br />

- A.K. Whitfield. Historical movements and <strong>migration</strong>s of <strong>Mugil</strong> cephalus in the St Lucia<br />

Lake system, South Africa.<br />

- K. Anastasopoulou. Movements of <strong>Mugil</strong> cephalus in the Hellenic waters.<br />

- Discussion on methods for <strong>migration</strong> <strong>studies</strong> on <strong>Mugil</strong> cephalus.<br />

16h00 - 16h15<br />

Coffee break<br />

16h15 - 17h00<br />

- Otolith dissection of <strong>Mugil</strong> cephalus from the Mediterranean specimens for<br />

microchemistry analysis.<br />

DINNER free<br />

Thursday 27 September 2007 – Otolith microchemistry<br />

9h - 10h30<br />

- Otolith preparation of samples of <strong>Mugil</strong> cephalus collected within <strong>MUGIL</strong> for bulk and<br />

surface analysis (embedding, sectioning). Overview of standard protocols.<br />

10h30 - 10h45<br />

Coffee break<br />

10h45 - 12h30<br />

- Bulk analysis of samples of <strong>Mugil</strong> cephalus collected within <strong>MUGIL</strong> using SB-ICPMS<br />

(Solution Based Inductively Coupled Plasma Mass Spectrometry) at the ISTEEM<br />

laboratory (UM2).<br />

12h30 - 14h00<br />

LUNCH at <strong>Montpellier</strong> 2 University<br />

14h00 - 16h00<br />

- Bulk analysis of samples of <strong>Mugil</strong> cephalus collected within <strong>MUGIL</strong> using SB-ICPMS<br />

(Solution Based Inductively Coupled Plasma Mass Spectrometry) at the ISTEEM<br />

laboratory (UM2).<br />

- Data treatment: from raw data to clean data (limits of detection, precision of<br />

measurement and standards).<br />

16h00 - 16h15<br />

Coffee break<br />

16h15 - 17h00


- Discussion on otolith microchemistry protocols for <strong>migration</strong> <strong>studies</strong> on <strong>Mugil</strong><br />

cephalus.<br />

DINNER free<br />

Friday 28 September 2007<br />

9h - 10h00<br />

- Synthesis on the application of otolith microchemistry to <strong>migration</strong> <strong>studies</strong> of <strong>Mugil</strong><br />

cephalus.<br />

10h00 - 10h30<br />

- Comparison of the different methods to study <strong>migration</strong> within <strong>MUGIL</strong>: otolith<br />

microchemistry, telemetry, genetics, fishery data, biomarkers. How can these<br />

methods be made complementary within <strong>MUGIL</strong>?<br />

10h30 - 10h45<br />

Coffee break<br />

10h45 - 12h30<br />

- WS3 report.<br />

12h30 - 14h00<br />

LUNCH at <strong>Montpellier</strong> 2 University<br />

14h00 - 16h00<br />

- Working group on the preparation of a new proposal to be submitted to the EU.<br />

16h00 - 16h15<br />

Coffee break<br />

16h15 - 17h00<br />

- WS3 report finalisation<br />

<strong>MUGIL</strong> DINNER (with confirmation)<br />

Saturday 29 September 2007<br />

9h00 - 17h00<br />

- Visit of the Sète fishing habour and the lagoons of the area.


3. List of participants<br />

Name Institute Country <strong>MUGIL</strong><br />

N°<br />

Date of<br />

Arrival<br />

Date of<br />

Departure<br />

Jacques PANFILI IRD France 1 25/09/07 29/09/07<br />

Javier TOMÁS IRD Spain 1 25/09/07 29/09/07<br />

Jean-Dominique DURAND IRD France 1 25/09/07 29/09/07<br />

Laurent VIGLIOLA IRD France 1 25/09/07 29/09/07<br />

Catherine ALIAUME CNRS-UM2 France 4 25/09/07 29/09/07<br />

Patrick BERREBI CNRS France 4 25/09/07 29/09/07<br />

Audrey DARNAUDE CNRS France 4 25/09/07 29/09/07<br />

Pape Samba DIOUF WWF-Wamer Senegal 5 23/09/07 30/09/07<br />

Beatriz MORALES NIN IMEDEA UIB Spain 10 25/09/07 29/09/07<br />

Wann-Nian TZENG IFS-NTU Taiwan 12 24/09/07 29/09/07<br />

Chia-Hui WANG IFS-NTU Taiwan 12 24/09/07 29/09/07<br />

Katerina ANASTASOPOULOU HCMR Greece 13 25/09/07 29/09/07<br />

Alan WHITFIELD SAIAB S. Africa 14 25/09/07 30/09/07<br />

Paul COWLEY SAIAB S. Africa 14 25/09/07 30/09/07<br />

Meeting venue<br />

Laboratoire ECOLAG - UMR 5119 - <strong>Université</strong> <strong>Montpellier</strong> 2 - cc 093 - Place E. Bataillon -<br />

34095 <strong>Montpellier</strong> Cedex 5 - France<br />

Tel +33 (0)4 67 14 41 23 (J. Panfili) / +33 (0)4 67 14 37 05 (secretary)<br />

Web: http://www.ecolag.univ-montp2.fr/<br />

Hotel venue<br />

HOTEL IBIS MONTPELLIER COMÉDIE - Le Triangle - allée Jules Milhau -<br />

34000 <strong>Montpellier</strong> - France<br />

Tel +33 (0) 4 99 13 29 99<br />

Fax +33 (0) 4 67 58 77 50<br />

Web: http://www.ibishotel.com/ibis/fichehotel/gb/ibi/0592/fiche_hotel.shtml<br />

Transport = 5-10 min walk from TGV train station - 15-20 min drive from the airport (taxi fee = 15-25 €)

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