scholarly journals Measurement Error Affects Risk Estimates for Recruitment to the Hudson River Stock of Striped Bass

2002 ◽  
Vol 2 ◽  
pp. 238-253 ◽  
Author(s):  
Dennis J. Dunning ◽  
Quentin E. Ross ◽  
Stephan B. Munch ◽  
Lev R. Ginzburg
Keyword(s):  
Measurement Error ◽  
Mortality Rate ◽  
Striped Bass ◽  
Power Plants ◽  
Fishery Management ◽  
Hudson River ◽  
Management Plan ◽  
Fishing Mortality ◽  
Beach Seine ◽  
Indian Point

We examined the consequences of ignoring the distinction between measurement error and natural variability in an assessment of risk to the Hudson River stock of striped bass posed by entrainment at the Bowline Point, Indian Point, and Roseton power plants. Risk was defined as the probability that recruitment of age-1+ striped bass would decline by 80% or more, relative to the equilibrium value, at least once during the time periods examined (1, 5, 10, and 15 years). Measurement error, estimated using two abundance indices from independent beach seine surveys conducted on the Hudson River, accounted for 50% of the variability in one index and 56% of the variability in the other. If a measurement error of 50% was ignored and all of the variability in abundance was attributed to natural causes, the risk that recruitment of age-1+ striped bass would decline by 80% or more after 15 years was 0.308 at the current level of entrainment mortality (11%). However, the risk decreased almost tenfold (0.032) if a measurement error of 50% was considered. The change in risk attributable to decreasing the entrainment mortality rate from 11 to 0% was very small (0.009) and similar in magnitude to the change in risk associated with an action proposed in Amendment #5 to the Interstate Fishery Management Plan for Atlantic striped bass (0.006)— an increase in the instantaneous fishing mortality rate from 0.33 to 0.4. The proposed increase in fishing mortality was not considered an adverse environmental impact, which suggests that potentially costly efforts to reduce entrainment mortality on the Hudson River stock of striped bass are not warranted.

From Catastrophe to Recovery: Stories of Fishery Management Success

2019 ◽  
Keyword(s):  
Striped Bass ◽  
Fishery Management ◽  
Hudson River ◽  
Management Plan ◽  
Lessons Learned ◽  
Juvenile Abundance ◽  
Spawning Stock ◽  
Long Term Monitoring ◽  
Term Monitoring

<i>Abstract</i>.—The Striped Bass <i>Morone saxatilis</i> is an extremely important commercial and recreational species with a coastal migratory stock in the United States referred to as “Atlantic Striped Bass” managed by the Atlantic States Marine Fisheries Commission (ASMFC). Atlantic Striped Bass has four major contributing stocks, including the Chesapeake Bay, which comprises 70–90%, and the Hudson River, the Delaware River, and the Albemarle Sound/Roanoke River (A/R). The collapse of Atlantic Striped Bass in the late 1970s precipitated federal funding and legislation like the Emergency Striped Bass Study for research on causative factors of the decline and potential management recommendations. The 1981 ASMFC Interstate Fishery Management Plan (ISFMP) for Atlantic Striped Bass was nonmandatory and mostly ineffective until the 1984 Atlantic Striped Bass Conservation Act provided regulatory authorities to the ASMFC and the federal government to close fisheries in states out of compliance with ISFMPs. Restrictions and moratoria on harvest imposed in several states reduced mortality, and under favorable environmental conditions and given Striped Bass life history, multiple years of good recruitment occurred. This allowed target thresholds for female spawning stock biomass to be achieved and the ASMFC to declare recoveries of Atlantic Striped Bass stocks from 1995 to 1998. Regulation of river flows was particularly important for the A/R stock recovery, and this stock is presented as a case study. During the 20+ years following recovery, long-term monitoring by states in support of adaptive management was primarily supported by the stable, nonappropriated funding of the Sport Fish Restoration Act. Monitoring includes spawning stock characterization and biomass estimation, juvenile abundance surveys, cooperative coastwide tagging, and harvest data collection. Future issues facing the recovered Atlantic Striped Bass include interspecies effects of relatively high abundance, management of stocks separately instead of as a single coastal stock, and ecosystem-based fisheries management. Key lessons learned in the Atlantic Striped Bass recovery are that high societal value of the species provided the political impetus to create and fund the recovery program, coordination of management and enforcement efforts among all jurisdictions was essential for this migratory species, and fully funded long-term monitoring programs are critical to adaptive population management.

Hudson River Fishes and their Environment

2006 ◽  
Keyword(s):  
New York ◽  
Mortality Rate ◽  
Power Plants ◽  
Long Island ◽  
Hudson River ◽  
Long Island Sound ◽  
East River ◽  
Bay Anchovy ◽  
Eggs And Larvae ◽  
Island Sound

<em>Abstract.</em>—Our objectives were to examine the distribution and abundance of bay anchovy <em>Anchoa mitchilli </em>eggs and larvae in the Hudson River and nearby waterways and to determine if past conditional mortality rate (CMR) estimates for bay anchovy entrained at Hudson River power plants may be substantially biased because they were based solely on sampling in the Hudson River. We addressed these objectives by comparing ichthyoplankton samples collected in the Hudson River with those collected in New York Harbor, the East River, and Long Island Sound using the same gear during 2002. Bay anchovy eggs were collected from late April through the end of sampling in the Hudson River (early October) and through the end of sampling in nearby waterways (late July). Bay anchovy larvae were collected from early June through end of sampling in both the Hudson River and nearby waterways. The highest densities of bay anchovy eggs and larvae in nearby waterways were about 13 and 14 times greater, respectively, than the highest densities in the lower Hudson River. The peak standing crops of bay anchovy eggs and larvae in nearby waterways were about eight times larger than those in the Hudson River. Therefore, past CMR estimates for bay anchovy entrained at Hudson River power plants may be substantially biased if the bay anchovy eggs and larvae collected in the Hudson River and nearby waterways during 2002 belonged to one population, as it appears they did, and 2002 was representative of other years.

Sustainability assessment for fishing effects (SAFE) on highly diverse and data-limited fish bycatch in a tropical prawn trawl fishery

2009 ◽  
Vol 60 (6) ◽  
pp. 563 ◽  
Author(s):  
Shijie Zhou ◽  
Shane P. Griffiths ◽  
Margaret Miller
Keyword(s):  
Mortality Rate ◽  
Fishery Management ◽  
Sustainability Assessment ◽  
Cost Effective ◽  
Mortality Rates ◽  
Assessment Method ◽  
Reference Points ◽  
Fishing Mortality ◽  
Point Estimates ◽  
Large Numbers

A new sustainability assessment for fishing effects (SAFE) method was used to assess the biological sustainability of 456 teleost bycatch species in Australia’s Northern Prawn Fishery. This method can quantify the effects of fishing on sustainability for large numbers of species with limited data. The fishing mortality rate of each species based on its spatial distribution (estimated from detection/non-detection data) and the catch rate based on fishery-dependent or fishery-independent data were estimated. The sustainability of each species was assessed by two biological reference points approximated from life-history parameters. The point estimates indicated that only two species (but 21 when uncertainty was included) had estimated fishing mortality rates greater than a fishing mortality rate corresponding to the maximum sustainable yield. These two species also had their upper 95% confidence intervals (but not their point estimates) greater than their minimum unsustainable fishing mortality rates. The fact that large numbers of species are sustainable can be attributed mainly to their wide distributions in unfished areas, low catch rates within fished areas and short life spans (high biological productivity). The present study demonstrates how SAFE may be a cost-effective quantitative assessment method to support ecosystem-based fishery management.

Incorporating Uncertainty into Fishery Models

2002 ◽  
Keyword(s):  
Fishery Management ◽  
Population Analysis ◽  
Management Plan ◽  
Atlantic Menhaden ◽  
Production Model ◽  
Fishing Mortality ◽  
Juvenile Abundance ◽  
Stock Assessments ◽  
Mortality Projections ◽  
Production Modeling

<em>Abstract.—</em>Stock assessments of Atlantic menhaden are conducted annually for the Atlantic States Marine Fisheries Commission, as required by the recently updated Fishery Management Plan, adopted in 1992. Uncertainties in stock assessments have been explored over the years from many perspectives. Two general areas of analysis are considered here. The first area is largely deterministic and concerns the virtual population analysis (VPA), including development and coherence of the catch-at-age matrix; historical retrospective problems; implications of assuming constant <EM>M </EM>at all ages analyzed; and reliability of recruitment estimates relative to fishery-independent juvenile abundance indices when used for calibrating the VPA. The second area of consideration comprises stochastic analyses, including stochastic projections based on biological benchmarks determined from yield-per-recruit and spawning-stockbiomass- per-recruit models; bootstrapped application of a surplus-production model; and projections from that production model. Nonetheless, the largest uncertainty in assessment of the stock stems not from modeling considerations, but is a biological question: Can the high stock levels observed in the 1950s be regained by reducing fishing mortality? Projections based on production modeling assume that they can, but if exogenous forces (for example, habitat loss or pollution) have affected the stock, it may be that they cannot. If the recent pattern of lower fishing mortality rates in response to social and economic factors continues, the fishery will in essence conduct an experiment that may answer the question.

scholarly journals Interactions between striped bass (Morone saxatilis) rebuilding programmes and the conservation of Atlantic salmon (Salmo salar) and other anadromous fish species in the USA

2006 ◽  
Vol 63 (7) ◽  
pp. 1346-1352 ◽  
Author(s):  
Douglas E. Grout
Keyword(s):  
Atlantic Salmon ◽  
New England ◽  
Striped Bass ◽  
Fish Species ◽  
Fishery Management ◽  
Atlantic Coast ◽  
Management Plan ◽  
Anadromous Fish ◽  
The Us ◽  
The Impact

Abstract Anadromous populations of striped bass occur along the Atlantic coast of the US from Maine to North Carolina. Recruitment overfishing and declining water quality led to substantial reductions in striped bass abundance during the 1970s and 1980s. Cooperative interstate fishery management of striped bass began in 1981, with the development of a fishery management plan by the Atlantic States Marine Fisheries Commission, an organization of Atlantic coastal states. Effective fishery management and additional research and monitoring contributed to a tenfold increase in abundance of striped bass stocks by the late 1990s. This dramatic increase resulted in increased predation on a variety of anadromous fish species including American shad, blueback herring, and alewives. Predation by striped bass on Atlantic salmon smolts in North America has been documented, but the impact of this predation has not been quantified. Moderate to strong correlations were found between estimates of striped bass abundance and the return of Atlantic salmon to three of the four major New England salmon rivers. Further research is required to quantify the proportion of smolt production consumed by striped bass, particularly for salmon populations listed as endangered under the US Endangered Species Act.

Emamectin benzoate is a safe and effective anthelmintic against coelomic nematode Philometra rubra in striped bass Morone saxatilis

2020 ◽  
Vol 142 ◽  
pp. 47-53
Author(s):  
K Béland ◽  
G Séguin ◽  
S Lair
Keyword(s):  
Mortality Rate ◽  
Striped Bass ◽  
High Mortality ◽  
Morone Saxatilis ◽  
Treatment Results ◽  
Emamectin Benzoate ◽  
Once Daily ◽  
Fish Hatchery ◽  
Parasitic Burden

An unusually high mortality rate due to verminous (Philometra rubra) coelomitis was documented in wild-hatched striped bass Morone saxatilis raised in a fish hatchery as part of a stock restoration program. To decrease the parasitic burden and therefore potentially minimize mortality, the effectiveness of 2 different anthelmintics was evaluated. Two trials were conducted on wild-collected fingerlings naturally infected by P. rubra. In 2006, 144 yearling fish were randomly assigned to 4 experimental groups: (1) levamisole (Levasol®) at 2 mg l-1 via immersion for 8 h once weekly for 3 wk; (2) levamisole at a dose of 2.5 mg kg-1 biomass via feed once daily for 7 d; (3) emamectin benzoate (Slice®) at a dose of 0.05 mg kg-1 biomass via feed once daily for 7 d; and (4) control. Emamectin successfully eliminated live nematodes in 84.9% of the fish, whereas the administration of levamisole, either via immersion or feed, was not successful in significantly reducing the number of live P. rubra. In 2007, the administration of the same dosage of emamectin to approximately 1000 naturally infected yearling striped bass was associated with a 100% mortality rate of P. rubra in the 30 fish randomly examined 5 wk after the beginning of the treatment. Results of these trials indicate that, at the dosage used, the administration of emamectin at the end of the summer is safe for striped bass yearlings and considerably reduces the prevalence and intensity of the infection by this parasite.

scholarly journals Can stock–recruitment points determine which spawning potential ratio is the best proxy for maximum sustainable yield reference points?

2013 ◽  
Vol 70 (6) ◽  
pp. 1075-1080 ◽  
Author(s):  
Christopher M. Legault ◽  
Elizabeth N. Brooks
Keyword(s):  
Life History ◽  
Mortality Rate ◽  
Maximum Sustainable Yield ◽  
Reference Points ◽  
Sustainable Yield ◽  
Marine Science ◽  
Fishing Mortality ◽  
Scatter Plots ◽  
Stock Recruitment ◽  
Spawning Potential Ratio

Abstract Legault, C. M., and Brooks, E. N. 2013. Can stock–recruitment points determine which spawning potential ratio is the best proxy for maximum sustainable yield reference points? – ICES Journal of Marine Science, 70: 1075–1080. The approach of examining scatter plots of stock–recruitment (S–R) estimates to determine appropriate spawning potential ratio (SPR)-based proxies for FMSY was investigated through simulation. As originally proposed, the approach assumed that points above a replacement line indicate year classes that produced a surplus of spawners, while points below that line failed to achieve replacement. In practice, this has been implemented by determining Fmed, the fishing mortality rate that produces a replacement line with 50% of the points above and 50% below the line. A new variation on this approach suggests FMSY proxies can be determined by examining the distribution of S–R points that are above or below replacement lines associated with specific SPRs. Through both analytical calculations and stochastic results, we demonstrate that this approach is fundamentally flawed and that in some cases the inference is diametrically opposed to the method's intended purpose. We reject this approach as a tool for determining FMSY proxies. We recommend that the current proxy of F40% be maintained as appropriate for a typical groundfish life history.

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