The Spot Prawn Fishery: A Status Report - Earth Economics

The Spot Prawn Fishery: A Status Report
•Prawn pots may be longlined or fished individually,
at least one buoy must be attached, and the
buoy must be marked per ADFG regulations.
•The use of pot gear is subject to a number of
restrictions, which include:
❍Pots may not have more than one bottom, a
vertical height of more than 24 in., and more
than four tunnel openings that individually
do not exceed 15 in. in perimeter.
❍Pots must be entirely covered with net webbing
or rigid mesh that is 1.75-in. stretch
mesh so as to facilitate the escapement of
prawn of less than 30 mm (1.2 in.) carapace
length. The mesh restriction does not apply
to the waters of Lituya Bay in District 16.
❍The number of pots fished per vessel is restricted
to 140 small pots (bottom perimeter
of no more than 124 in.) or 100 large pots
(bottom perimeter of no more than 153 in.).
If any pot on the vessels falls into the large
pot category, the vessel is restricted to 100
pots. All pots on a vessel must be the same
size and type.
❍All pots must be tagged and registered, with
tags obtained at an ADFG office.
❍Simultaneously fishing other shrimp pots or
another type of commercial, sport, or personal
use pot is prohibited.
•The fishing season has been set for October
1–February 28, between the hours of 8:00 a.m.
and 4:00 p.m. The Fish Commissioner may open
a district to prawn fishing where the Guideline
Harvest Range has not been reached from May
15 through July 31.
Management Issues and Concerns
ADFG has expressed concerns regarding the serial
and/or localized depletion of certain elements of the
stock. “It is possible that fishers are maintaining
good harvests through improved gear and fishing
techniques and by exploiting different grounds, or
other means. The targeted harvest of the larger,
older, and most fecund prawns may be reducing
stock reproductive potential through removal. An
inappropriately high harvest rate and the removal
of large females may be forcing females to produce
their first clutch of eggs at a smaller size” (Koeneman
and Botelho 2000c). Serial depletion is a potential
concern for species, like spot prawns, that may have
limited distributions, as it may lead to unexpected,
precipitous declines in the population or overall biomass
(Orensanz et al. 1998).
According to ADFG, a conservative and more
informed management strategy is being developed
and implemented for southeastern Alaska’s spot
prawn fishery. Precaution is at the core of this system.
However, like any oceanic, open-system fishery,
complete enumeration is impossible. Research is
needed to define the physical, chemical, biological,
and temporal trends that influence and affect fisheries
production. This process requires time, money,
and dedication, and is a difficult but necessary challenge
(Love, ADFG. Pers. comm., May 2001).
One of the central challenges facing ADFG and the
management of spot prawns in Alaska is the establishment
of an adaptive research and management
system that can accurately predict future production
given ever-changing population dynamics
and demographics, while also preventing or rapidly
detecting localized depletion. Expansion of baseline
research is needed so that annual and area
trends and biologically derived GHLs can be established.
This type of data will allow for the determination
of stock status, the effects of fishing on
species and the environment, and ultimately will
play a central role in ensuring the long-term sustainability
of the fishery.
BRITISH COLUMBIA
SPOT PRAWN FISHERY
Biological Status of Spot Prawns
Fisheries and Oceans Canada (Fisheries and Oceans)
views the British Columbia (BC) inshore prawn
stocks as fully exploited. Commercial landings
data suggest a fairly consistent production trend.
Prawns are landed incidentally in offshore fisheries
for black cod, shrimp, and groundfish.
Although the actual distribution and abundance of
this stock is unknown, these landings provide evidence
for the existence of an offshore stock.
Fishers have a stated interest in investigating offshore
fishing areas, but increased effort and efficiency
have decreased inshore season length to
the point where explorative fishing opportunities
during the open inshore fishery are restricted
(Boutillier, Fisheries and Oceans Canada. Pers.
comm., March 2001). Exploratory fishing was carried
out in late summer and early fall 2001, but the
information collected was inconclusive.
Catch sampling is used to determine the biological
status of the spot prawn resource during the commercial
fishing season. Prawns in every second
or third trap on the fishing line are collected as
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