The ecology of eelgrass meadows in the Pacific Northwest: A ...

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Table 16. ( CDncluded) Spec ies year Amount of Harvest Value in $ kq (lbs) (U.S.) Mussels Sport harvest All hardshell clams (wet wt) Oysters Sport harvest (meats) $1.26/lb; Stokes (1978; 1975 prices) Oungeness crabs C m r ical harvest ( Puge t Sound ) Cormerical harvest ( Cbastal) Sport harvest Fed rock crabs $0.703/lb (ex vessel) $0.638/1b (ex vessel) $0.836/1b (ex vessel) $0.769/1b (ex vessel, Wstprt) $0.664/1b (ex vessel, Wstprt) $0.918/lb (ex vessel, Wstprt) $5.30/lb; Stokes (1978; 1975 prices) -- $2.65/1b: Stokes (1978; 1975 prices) replacement costs of most of the animals value as well. This aspect appears not to that result in income from the marine be well understood by the general public, environment, inany of which spend a part of who continue to place great demands upon their life cycle in eelgrass meadows in the various agencies to diversify its use. the Pacific Northwest. The amount of income generated from the harvests of these animals is staggering. Transplanting Programs Thus, as the harvest data for commercial It is possible that transplantation of and sport fisheries and game continue to seagrasses will adequately mitigate direct be collected and evaluated, it appears and/or direct inadvertent disturbances that the seagrass system has not only to the system. Recent work done by scientific value, but an enormous economic Fonseca et al. (1982b), using eelgrass on
a variety of substrates including dredged spoils in North Carolina, appears cost effective and may very well be successful in selected Pacific Northwest estuaries. The only work done in Puget Sound thus far (Phillips 1972; Backman 1983) involved only small experimental plots. m e and Hoeppel (1976) prepared an appraisal and recommendation for an eelgrass transplantation and restoration program in south San Diego Bay, California. In the absence of any available large-scale projects in which to assess transplant success and costs, they recommend that since transplantation has been shown to be feasible, a pilot study should be made on the 8-acre Delta Beach site using a variety of techniques. Go forth and Peeling (1979) conduct& the pilot project at the site. They established an initial sublittoral plot of 46 m2 to test the relative success of three plug sizes with the plants placed in biodegradable fiber pots. A second transplant was conducted to establish 1.62 ha (4 acres) of eelgrass in the intertidal and sublittoral zones, Survival of the potted plants was relatively high. After 30 mo there was 35%-46% survival of the plugs in the initial transplant. In the second transplant only 10% of the plugs survived in the subtidal after one growing season, while in the intertidal, plug survival ranged between 50%-75%. No one has had any success using eelgrass seeds in transplants e hilli ips 1972; Churchill et al. 1978). The seeds have a very low rate of germination at ambient seawater salinities, at least in the middle portions of its distribution, including locations on both coastlines where human-related impacts are the greatest; and field mortalities of seedlings are extremely high (Phillips 1972). Fonseca et al. (1982b) found very high survival and spread of eelgrass in North Carolina on fine sediments of dredge spoils. However, I would exercise caution in extrapolating their success in North Carolina to areas throughout the range of eelgrass on both coastlines in North America. In order to state that eelgrass can be successfully transplanted in a large mitigation project in the Pacific Northwest (>0.4 ha; 1.0 acre), at least one large-scale pilot project is needed. Phillips and Backman completed a large experimental transplanting project in Puget Sound, reported by Backman (1983). Although almost 200 small plots of eelgrass were monitored quarterly for over 2 yr for survival, growth, and phenology, their results cannot be used to determine possible success of a mitigation project.
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~~~/0~-84/24 September 1984 THE ECO
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PREFACE Nearly half the population
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CONTENTS PREFACE ..................
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FIGURES Number 1 2 ................
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ACKNOWLEDGMENTS I wish to acknowled
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Because eelgrass is a rooted plant,
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CHAPTER 1 THE PHYSIOGRAPHIC SETTING
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Table 1. Precipitation, temperature
Page 18 and 19:
Table 2. Distribution and extent of
Page 20 and 21:
Table 2. (Concluded) Extent of mat
Page 22 and 23:
CHAPTER 2 THE BIOLOGY OF EELGRASS 2
Page 24 and 25:
Table 4. Field observations on eelg
Page 26 and 27:
leaves overtopped them and created
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1.0- influence the redox potential
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Oxygen There are Little data to ind
Page 32 and 33: enough, increased erosion of bottom
Page 34 and 35: The terms used to describe biomass
Page 36 and 37: estimates are reported on work done
Page 38 and 39: Figure 10. Eelgrass at Blakely Isla
Page 40 and 41: increase in p~), and the sediments
Page 42 and 43: particulate matter and DOM were hig
Page 44 and 45: Table 9. Nutrient content of eelgra
Page 46 and 47: ecause it is dominated by a single
Page 48 and 49: epibenthos, and other components al
Page 50 and 51: shorebirds). From a recent thorough
Page 52 and 53: pink shrimp, and bottom fish (Proct
Page 54 and 55: Table 13 a. (Continued) Phyltnn, cl
Page 56 and 57: Phylum, class, and Resident or Livi
Page 58 and 59: Table 13b. (concluded) Resident or
Page 60 and 61: Table 13c. (Concluded) Living Feedi
Page 62 and 63: eelgrass) , while 29 species were f
Page 64 and 65: (239,d9~,9(ii9 kg) (outram and Huln
Page 66 and 67: Washington State Game Dept., pers.
Page 68 and 69: Table 15. Energy in various ccmpart
Page 70 and 71: Export of whole by waterfowl Figure
Page 72 and 73: storms erode and dislodge some eelg
Page 74 and 75: CHAPTER 6 HUMAN IMPACTS-MANAGEMENT
Page 76 and 77: apparent darnazje. IUllzomes and ro
Page 78 and 79: great annual range of water tempera
Page 80 and 81: 1978, for all assumptions, formulat
Page 84 and 85: REFERENCES Rdarns, S.M. 197va. The
Page 86 and 87: seagrass community. Pages 153-162 i
Page 88 and 89: on current flow. Estuarine Coastal
Page 90 and 91: Inst. Agric. Res., Tohoku Univ.: 13
Page 92 and 93: In flvt. seayrasses, l'halassia McR
Page 94 and 95: eelgrass (~ostera marina L. ) Phill
Page 96 and 97: along the Strait of Juan de Fuca. N
Page 98 and 99: diatom assemblages in Netarts Bay,
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