Atlantic States Marine Fisheries Commission Research Articles

Building confidence: Developing image-based methods to incorporate fishery-collected data in the American lobster stock assessment

The American lobster, Homarus americanus, supports the most valuable single-species fishery in North America; however to-date, a reliable and robust method to determine age does not exist, and thus some of the more traditional catch-at-age stock assessment methods cannot be used to determine status. In lieu of this, the Atlantic States Marine Fisheries Commission’s American Lobster Stock Assessment Model uses a probabilistic growth transition matrix to determine how lobsters of different sizes will grow and recruit into the fishery. Developing and updating the growth transition matrix to reflect current growth dynamics requires estimates of molt increment and interval. Tagging studies are an inexpensive method to collect this type of information, but relying on fishing industry reported recapture data and buy-in can be challenging, resulting in varied return rates and uncertainty in measurement accuracy. Here, we report on a subset of recaptured lobsters released in the Gulf of Maine and Georges Bank regions between 2015 and 2020, where in addition to recapture locations, harvesters were encouraged to submit images of recaptured lobsters alongside a standard lobster gauge as a scale to estimate carapace length. Some fishermen were able to provide both direct measurements and images. Images were analyzed in ImageJ to estimate individual lobster carapace length (CL); and each image was assigned a quality score. For all groups, image-derived lengths were correlated with measured observations, regardless of the overall image quality, with only a slight underestimation at the maximum end of CL. This image-based method for length estimation provides high-quality length predictions regardless of image quality and can significantly increase the likelihood of harvesters contributing data with broad potential to engage commercial fisherman in collaborative science. Using this method we were able to expand the dataset of length records from this project by 251 or 33 %, providing additional data at a rate similar to tagging an additional 6000 lobsters.

Food supplementation increases reproductive performance of ospreys in the lower Chesapeake Bay

The Atlantic States Marine Fisheries Commission (ASMFC), the governing body responsible for managing fisheries on the U.S. East Coast, formally adopted the use of Ecological Reference Points (ERPs) for Atlantic menhaden, Brevoortia tyrannus. Scientists and stakeholders have long recognized the importance of menhaden and predators such as ospreys, Pandion haliaetus, that support the valuable ecotourism industry and hold cultural significance. Landings in the reduction fishery are at their lowest levels and menhaden is facing potential localized depletion. Mobjack Bay, located within the lower Chesapeake Bay, has been a focus of osprey research since 1970 and represents a barometer for the relationship between osprey breeding performance and the availability of their main prey, menhaden. Since local levels of menhaden abundance were not available, we conducted a supplemental menhaden feeding experiment on osprey pairs during the 2021 breeding season. Our main objective was to determine if the delivery rate of menhaden had an influence on nest success and productivity. Nest success (χ2 = 5.5, df = 1, P = 0.02) and productivity (β = 0.88, SE = 0.45, CI = 0.049, 1.825, P = 0.048) were significantly higher within the treatment group. Reproductive rates within the control group were low and unsustainable suggesting that current menhaden availability is too low to support a demographically stable osprey population. Menhaden populations should be maintained at levels that will sustain a stable osprey population in which they are able to produce 1.15 young/active nest to offset mortality.

The Path to an Ecosystem Approach for Forage Fish Management: A Case Study of Atlantic Menhaden

Atlantic menhaden (Brevoortia tyrannus) support the largest fishery by volume on the United States East Coast, while also playing an important role as a forage species. Managers’ and stakeholders’ increasing concerns about the impact of Atlantic menhaden harvest on ecosystem processes led to an evolution in the assessment and management of this species from a purely single-species approach to an ecosystem approach. The first coastwide stock assessment of Atlantic menhaden for management used a single-species virtual population analysis (VPA). Subsequent assessments used a forward projecting statistical catch-at-age framework that incorporated estimates of predation mortality from a multispecies VPA while analytical efforts continued toward the development of ecosystem models and explicit ecological reference points (ERPs) for Atlantic menhaden. As an interim step while ecosystem models were being developed, a series of ad hoc measures to preserve Atlantic menhaden biomass for predators were used by managers. In August 2020, the Atlantic States Marine Fisheries Commission formally adopted an ecological modeling framework as a tool to set reference points and harvest limits for the Atlantic menhaden that considers their role as a forage fish. This is the first example of a quantitative ecosystem approach to setting reference points on the United States Atlantic Coast and it represents a significant advance for forage fish management. This case study reviews the history of Atlantic menhaden stock assessments and management, outlines the progress on the current implementation of ERPs for this species, and highlights future research and management needs to improve and expand ecosystem-based fisheries management.

A comparison of the size at maturity of female American lobsters (Homarus americanus) over three decades and across coastal areas of the Gulf of Maine using ovarian staging

Abstract The carapace length (CL) at which American lobster (Homarus americanus) females reach maturity can be used to evaluate egg production, growth patterns, and the overall health of lobster stocks. The female maturity datasets used to represent Gulf of Maine (GOM) lobsters in the 2015 Atlantic States Marine Fisheries Commission American Lobster Stock Assessment were collected in the 1990s by the Maine Department of Marine Resources at two coastal sites. Many studies have demonstrated an inverse relationship between temperature and the size at maturity in female lobsters, and GOM waters have warmed significantly over this period. To update these GOM maturity datasets, we used ovarian staging to determine the maturity status of over 1200 females from fives sites over 3 years. Broad application of this methodology in tandem with key growth measurements on females 50–120 mm CL allowed us to characterize reproductive development and generate maturity ogives (proportion mature at a given CL). We observed a latitudinal gradient in the size at maturity across this coastal region of the GOM and quantified a decrease in this size over 25 years. These findings have implications for future stock assessment approaches and management measures implemented to sustain this valuable fishery.

Balancing Model Complexity, Data Requirements, and Management Objectives in Developing Ecological Reference Points for Atlantic Menhaden

Atlantic menhaden is an important forage fish and the target of the largest fishery along the US East Coast by volume. Since 1999, managers at the Atlantic States Marine Fisheries Commission, stakeholders, and scientists have been interested in developing ecological reference points (ERPs) that account for menhaden’s role as a forage species. To accomplish this, we developed a suite of modeling approaches that incorporated predation on menhaden and changes in productivity over time and allowed for evaluation of trade-offs between menhaden harvest and ecosystem management objectives. These approaches ranged in complexity, from models with minimal data requirements and few assumptions to approaches with extensive data needs and detailed assumptions. This included a surplus production model with a time-varying intrinsic growth rate, a Steele-Henderson surplus production model, a multispecies statistical catch-at-age model, an Ecopath with Ecosim (EwE) model with a limited predator and prey field, and a full EwE model. We evaluated how each model could address managers’ objectives and compared outputs across the approaches, highlighting their strengths, weaknesses, and management utility. All models produced estimates of age-1 + biomass and exploitation rate that were similar in trend and magnitude to the single-species statistical catch-at-age model, especially in recent years. While the less complex models were relativity easy to implement and update, they lacked key elements needed to manage multiple species simultaneously. More complex models required a wider array of data and were more difficult to update within the current management time-frames, but produced a more useful framework for managers. Ultimately, an EwE model of intermediate complexity coupled with the existing single-species assessment model was recommended for use in management.

The Long-Term Effect of Bleeding for Limulus Amebocyte Lysate on Annual Survival and Recapture of Tagged Horseshoe Crabs

In the U.S., 525,000 horseshoe crabs (Limulus polyphemus) per year have been captured during 2013–2017, brought to biomedical facilities, and bled to produce Limulus amebocyte lysate (LAL), then mostly released to the area of capture. The Atlantic States Marine Fisheries Commission estimates short-term bleeding-induced mortality to be 15% (4% to 30%), resulting in mortality of approximately 78,750 horseshoe crabs annually in recent years comprising a minor portion (<13%) of the up to one million annual coastwide landings dominated by harvest for bait. However, the long-term effect of bleeding for LAL on annual survival and spawning behavior is unknown; thus, results from short-term studies alone might underestimate bleeding effects at the population level. To address this knowledge gap, we analyzed data from the U.S. Fish and Wildlife horseshoe crab tagging database to estimate the differences in survival and recapture rates of bled and not bled horseshoe crabs tagged in the same years and geographic area. Contrary to expectation, survival was not lower for bled crabs compared to unbled crabs. Differences varied, but survival estimates tended to be higher for bled crabs than for unbled crabs. However, biomedical culling and selection for younger or healthier animals could have resulted in biomedically tagged individuals representing a healthier subset of the overall population with subsequent higher survival. Furthermore, the tagging analysis revealed a post-bleeding reduction in capture probability, which could indicate decreased spawning activity, evident in males more than females. Continued tagging of bled and unbled crabs in the same geographic area while recording age class and sex will contribute to the further resolution of LAL production’s effect on horseshoe crab populations.

Genetic Evaluation of Population Structure in Tautog

AbstractTautog Tautoga onitis supports both recreational and growing commercial fisheries from Virginia to Massachusetts. Tautogs, which aggregate around structured habitats (wrecks, rocks, bridge pilings, etc.), are slow to mature and have a low reproductive rate relative to other teleosts. Slow growth and easy catchability result in Tautogs being extremely vulnerable to overexploitation, and their populations are slow to rebuild. At present, Tautogs are managed by the Atlantic States Marine Fisheries Commission as four separate regions: Massachusetts–Rhode Island, Long Island Sound, New Jersey–New York Bight, and Delaware–Maryland–Virginia, despite a lack of genetic information to support this management scenario. The objective of the current study was to investigate the genetic connectivity of Tautogs throughout their management zone and provide stock structure information in support of fisheries management. We developed and used 18 variable microsatellite loci to evaluate the genetic structure of 789 Tautogs sampled across their effective U.S. East Coast range from Massachusetts to North Carolina. We also amplified and sequenced a 1,267 base pair portion of the mitochondrial DNA control region from Tautogs sampled from Massachusetts and Virginia. Comparison of pairwise FST values among samples collected from locations south of Cape Cod, Massachusetts, were low and nonsignificant, suggesting that gene flow is sufficient to prevent the accumulation of genetic differences. The collection from Cape Cod Bay, Massachusetts, was genetically distinct from all other samples (FST = 0.021 to 0.046), indicating that Cape Cod is a significant barrier to dispersal for Tautogs and suggesting that Tautogs north and south of Cape Cod should be managed as separate stocks.

Trends in Abundance and Fishing Mortality of American Eels

A range of findings on the status of American Eels Anguilla rostrata has been published. The most extreme report occurred in 2014, when the International Union for the Conservation of Nature placed the species on its Red List, meaning that the Union considered it endangered. The trend in abundance of American Eels is consequently of concern for conservation biology and fishery management. Here, I present a new index of American Eel relative abundance in the estuarine waters along the U.S. Atlantic coast from 1981 through 2014, consisting of the total American Eel catch per trip by recreational anglers. Abundance was highest in 1981 and then declined through 1995 to about one‐sixth of the 1981 value. By 2003, abundance began an irregular increase; by 2014, it was approximately one‐half of the 1981 value. Combining commercial landings with the index of relative abundance produces the trend in fishing mortality, which has been relatively low during both the period of declining abundance and the period of increasing abundance, although it increased temporarily during the period of lower abundance from 1995 through 2002. I include a discussion of the Atlantic States Marine Fisheries Commission's 2012 stock assessment and explore some general issues in stock assessment of American Eels.

Exploring Causal Factors of Spawning Stock Mortality in a Riverine Striped Bass Population

AbstractThe recovery of the Atlantic Striped Bass Morone saxatilis stock in the 1990s is an important example of effective natural resources management. Implementation of Atlantic States Marine Fisheries Commission (ASMFC) harvest regulations reduced mortality, protected older and more fecund females, and contributed to the formation of dominant year‐classes in the 1980s and 1990s. However, Striped Bass stocks south of Albemarle Sound, North Carolina, are not subject to ASMFC management plans, and many populations have failed to attain recovery goals. Catch‐curve analyses indicate that the Neuse River Striped Bass population continues to experience spawning stock exploitation rates similar to those implicated in the decline of the Atlantic Migratory and Albemarle Sound/Roanoke River stocks in the 1970s. From 1994 to 2015, Striped Bass instantaneous fishing mortality (F) in the Neuse River ranged from 0.12 to 0.84 and exceeded the overfishing threshold (FThreshold = 0.41) in 12 of 22 years. A global linear model using environmental and exploitation factors accounted for 55% of the variability in spawning stock discrete annual mortality. An information‐theoretic approach was used to elucidate the best linear model for predicting discrete annual mortality. The best model included previous‐year gill‐net effort and same‐year commercial harvest (Akaike weight = 0.64, R2 = 0.50). Model‐averaged coefficients for gill‐net effort and commercial harvest suggested total exploitation impacts that were congruent with other studies of Neuse River Striped Bass. Results indicate that reducing exploitation to target levels will require substantial reductions in gill‐net effort in areas of the Neuse River where Striped Bass occur. Reducing exploitation may increase spawning stock biomass and advance the age structure of spawning females, conferring an increased likelihood of successful recruitment and production of dominant year‐classes during periods of favorable environmental conditions.

Historical Review of Commercial Fishery Regulations for Striped Bass (Morone saxatilis Walbaum) in Massachusetts

Since the arrival of Pilgrims in 1620, Morone saxatilis (Striped Bass) has been an important commercial fish species for residents of Massachusetts. Early attempts by the Plymouth Colony to develop fishery commerce by selling Striped Bass products to Spain failed. Viable domestic markets for Striped Bass were established by the 18th century and continue to present day. Application of laws to control the commercial harvest of Striped Bass to address local declines in abundance first appeared in the Massachusetts Acts and Resolves in the late 18th century, and most laws restricted the taking of Striped Bass by seines. In 1945, a temporary Massachusetts law prohibiting the taking of Striped Bass by any method other than hook-and-line was made permanent. More-restrictive size and quota regulations were not imposed until the early 1980s as inter-state conservation efforts responded to the declining trends in coastal stocks. In present day, the Striped Bass commercial fishery in Massachusetts is regulated by minimum size and quotas established under the Atlantic States Marine Fisheries Commission's Striped Bass Management Plan and by state no-take days and daily bag limits.

Running Silver: Restoring Atlantic Rivers and their Great Fish Migrations

49 Anadromous salmon in the Pacific and Atlantic oceans are iconic species that have been the subjects of numerous natural science texts that narratively describe their common plight. Among my favorites is Bruce Brown’s Mountain in the Clouds: A Search for Wild Salmon. Reading this book is one reason that I became passionate about wild salmon conservation. However, there has been a gap in this narrative for the eastern United States, where Atlantic Salmon Salmo salar is only part of a mosaic of ocean-going species. Running Silver is an intriguing read that fills this void. The book weaves the story of the plight of Northwest Atlantic diadromous fish with source material as varied as Thoreau and Atlantic States Marine Fisheries Commission management actions. Despite the diverse sources, this narrative achieves the author’s goal of explaining the demise of this complex of species while trying to restore biological and cultural awareness of what has been lost ... and could be restored. John Waldman’s passion and dedication to the sea run fish community (both the fish and the people) is apparent in each of the book’s 20 relatively short 10-20 page chapters. Although they are woven together into a compelling story, most of the chapters are largely independent, allowing easy reading in small doses. The text transitions between number heavy text needed to explain harsh facts of lost abundance and hectares of concrete that block Atlantic Ocean rivers to very personal narrative observations of fish and river systems. I particularly appreciated the frequent conversational text where Waldman related discussions and observations of river keepers, managers, and scientists. The reader feels as if they are at the table or the river’s edge. The first four chapters set the stage and describe the fish species and river systems of the Atlantic realm. Chapter 3, The Seasonal Parade, was a favorite. Waldman uses the annual sequence of migration to introduce the reader to both the primary diadromous species and some that may be better characterized as euryhaline wanderers. This chapter was concise yet nuanced in its description of diversity within and among diadromous fish in their ecology and habitat use. And who knew there were anadromous whitefish! Running Silver: Restoring Atlantic Rivers and their Great Fish Migrations BOOK REVIEW

Implementation of a framework for multi-species, multi-objective adaptive management in Delaware Bay

Decision analytic approaches have been widely recommended as well suited to solving disputed and ecologically complex natural resource management problems with multiple objectives and high uncertainty. However, the difference between theory and practice is substantial, as there are very few actual resource management programs that represent formal applications of decision analysis. We applied the process of structured decision making to Atlantic horseshoe crab harvest decisions in the Delaware Bay region to develop a multispecies adaptive management (AM) plan, which is currently being implemented. Horseshoe crab harvest has been a controversial management issue since the late 1990s. A largely unregulated horseshoe crab harvest caused a decline in crab spawning abundance. That decline coincided with a major decline in migratory shorebird populations that consume horseshoe crab eggs on the sandy beaches of Delaware Bay during spring migration. Our approach incorporated multiple stakeholders, including fishery and shorebird conservation advocates, to account for diverse management objectives and varied opinions on ecosystem function. Through consensus building, we devised an objective statement and quantitative objective function to evaluate alternative crab harvest policies. We developed a set of competing ecological models accounting for the leading hypotheses on the interaction between shorebirds and horseshoe crabs. The models were initially weighted based on stakeholder confidence in these hypotheses, but weights will be adjusted based on monitoring and Bayesian model weight updating. These models were used together to predict the effects of management actions on the crab and shorebird populations. Finally, we used a dynamic optimization routine to identify the state dependent optimal harvest policy for horseshoe crabs, given the possible actions, the stated objectives and our competing hypotheses about system function. The AM plan was reviewed, accepted and implemented by the Atlantic States Marine Fisheries Commission in 2012 and 2013. While disagreements among stakeholders persist, structured decision making enabled unprecedented progress towards a transparent and consensus driven management plan for crabs and shorebirds in Delaware Bay.

Regional fishery management organizations and large marine ecosystems

Regional fisheries management organizations (RFMOs) addressing the management of living marine resources have a long history, beginning in 1811 with the North Pacific Fur Seal Convention followed by the International Pacific Halibut Convention in 1924. Following the expansion of fisheries after WWII RFMOs proliferated and after the general acceptance of a 200 mile extended jurisdiction in the mid-1970s many more nations became involved. There are approximately 17 RFMOs, (depending on the definition of “management”) of the over 40 marine Regional Fisheries Bodies(RFBs) identified by FAO. The Large Marine Ecosystem (LME) approach has roots in the experience of the International Commission for the Conservation of Northwest Atlantic Fisheries (now defunct and replaced by the Northwest Atlantic Fisheries Organization (NAFO)) which pioneered ecosystem based fisheries management. The LME approach was fleshed out in the 1980s and initiated as both the Global Environment Facility (GEF) and country projects, beginning in the mid-1990s. LMEs have fisheries as a major component to be addressed under the LME five-module concept. As LME Programs enter the stage where they need to move to develop their governance responsibilities, the relationship with existing RFMOs is critical. This paper examines possibilities for this interaction with special attention to, but not exclusively, the Western coast of Africa. Possible inferences from the US east coast experience are also addressed, considering the Atlantic States Marine Fisheries Commission as a pseudo RFMO with the states assuming a role similar to countries.

Managing a Marine Stock Portfolio: Stock Identification, Structure, and Management of 25 Fishery Species along the Atlantic Coast of the United States

AbstractIn this review, stock identification methods used, resulting stock numbers and boundaries, and assessment and management context were explored for all 25 species managed by the Atlantic States Marine Fisheries Commission (ASMFC). This included invertebrates and vertebrates distributed between Maine and Florida, with a few species ranging across all these states and some ranging into the Gulf of Mexico and the Canadian Maritimes. The effects of larval dispersal or mixing of adults in the marine environment were evident. Marine and catadromous spawners were recognized and treated as a unit stock (e.g., northern shrimp Pandalus borealis, American Eel Anguilla rostrata, Atlantic menhaden Brevoortia tyrannus, Bluefish Pomatomus saltatrix, Tautog Tautoga onitis), a metapopulation (American lobster Homarus americanus, Atlantic Herring Clupea harengus), or two stocks, north and south of Cape Hatteras, a major biogeographic boundary, (Black Sea Bass Centropristis striata, Scup Stenotomus chrysops, Red Drum Sciaenops ocellatus, Summer Flounder Paralichthys dentatus). Estuarine and anadromous spawners were structured and managed at a finer spatial scale (horseshoe crab Limulus polyphemus, Atlantic Sturgeon Acipenser oxyrinchus, American Shad Alosa sapidissima and the river herrings Blueback Herring A. aestivalis and Alewife A. pseudoharengus, and Spotted Seatrout Cynoscion nebulosus). A broad suite of stock identification methods have been applied to ASMFC species and reviewed here in five categories: life history traits, other phenotypic traits, genetic traits, natural marks, and applied marks. An interdisciplinary mix of methods has been achieved for a few species (Striped Bass Morone saxatilis, Winter Flounder Pseudopleuronectes americanus), but only a few or no stock identification methods have been applied to others (Spiny Dogfish Squalus acanthias, Hickory Shad A. mediocris, Spot Leiostomus xanthurus, Spanish Mackerel Scomberomorus maculatus). Clinal phenotypic variation has contributed to several long‐standing debates about stock structure; some of these have been recently reevaluated as a unit stock (Atlantic Croaker Micropogonias undulatus, Weakfish Cynoscion regalis), and others are still debated. For some ASMFC species, other priorities (e.g., bycatch) dominate the uncertainty of the assessment or management process. Otherwise, stock identification remains a research priority for most of these species. Continued research of this subject should consider (1) research priorities tabulated by ASMFC review panels, (2) strategic use of interdisciplinary stock identification methods, (3) use of experiments or reaction norms to separate phenotypes from genotypes, (4) genetic surveys at a seascape scale, (5) demonstration of contingent (nongenetic) structure and its implications for management, and (6) simulation modeling. Obstacles to adopting finer‐scale structure into assessments or management of ASMFC fisheries include: (1) multiple stock units are apparent but boundaries are not clear, (2) monitoring requirements for smaller areas or for mixed‐stock catches are not cost effective, or (3) mixing rates within a metapopulation or across biogeographic boundaries are poorly described.Received May 8, 2013; accepted March 3, 2014

Evaluating a multispecies adaptive management framework: must uncertainty impede effective decision‐making?

Summary Application of adaptive management to complex natural resource systems requires careful evaluation to ensure that the process leads to improved decision‐making. As part of that evaluation, adaptive policies can be compared with alternative nonadaptive management scenarios. Also, the value of reducing structural (ecological) uncertainty to achieving management objectives can be quantified. A multispecies adaptive management framework was recently adopted by the Atlantic States Marine Fisheries Commission for sustainable harvest of Delaware Bay horseshoe crabs Limulus polyphemus, while maintaining adequate stopover habitat for migrating red knots Calidris canutus rufa, the focal shorebird species. The predictive model set encompassed the structural uncertainty in the relationships between horseshoe crab spawning, red knot weight gain and red knot vital rates. Stochastic dynamic programming was used to generate a state‐dependent strategy for harvest decisions given that uncertainty. In this paper, we employed a management strategy evaluation approach to evaluate the performance of this adaptive management framework. Active adaptive management was used by including model weights as state variables in the optimization and reducing structural uncertainty by model weight updating. We found that the value of information for reducing structural uncertainty is expected to be low, because the uncertainty does not appear to impede effective management. Harvest policy responded to abundance levels of both species regardless of uncertainty in the specific relationship that generated those abundances. Thus, the expected horseshoe crab harvest and red knot abundance were similar when the population generating model was uncertain or known, and harvest policy was robust to structural uncertainty as specified. Synthesis and applications. The combination of management strategy evaluation with state‐dependent strategies from stochastic dynamic programming was an informative approach to evaluate adaptive management performance and value of learning. Although natural resource decisions are characterized by uncertainty, not all uncertainty will cause decisions to be altered substantially, as we found in this case. It is important to incorporate uncertainty into the decision framing and evaluate the effect of reducing that uncertainty on achieving the desired outcomes.

At-sea determination of female American lobster (Homarus americanus) mating activity: Patterns vs. expectations

We examined female American lobsters (Homarus americanus) for evidence of mating activity in selected regions within Gulf of Maine (GOM) and Southern New England (SNE) waters. The presence of a spermatophore in their seminal receptacles was used as an indication of mating activity (spermatophore positive, “SP”). To determine if all presumably-mature females had mated, the proportion of females that were SP was compared to the size-at-maturity data used in the Atlantic States Marine Fisheries Commission (ASMFC) American Lobster Stock Assessment. A total of 1696 females were examined, and in all regions >75% of these females were SP. In most regions, more presumably-immature females (based on pre-existing maturity data) were SP than expected, while in the two SNE regions (Rhode Island) there were more presumably-mature females lacking sperm than expected. We suggest that due to the depleted condition of the SNE lobster stock, the discrepancy between expected maturity and mating activity in SNE females warrants further attention. Additionally, our data suggest that there is a need to re-examine lobster size-at-maturity throughout the GOM lobster stock. It appears as if either the maturity schedules have recently shifted, or sexually immature females are regularly mating in many regions.

A Fisherman's Perspective

A Fisherman's Perspective

The Benefits of Rationalization: The Case of the American Lobster Fishery

The American lobster (Homarus americanus) fishery is currently the most valuable fishery on the Atlantic coasts of both the USA and Canada based on ex-vessel value. Lobster conservation policies have traditionally focused on technical restrictions such as minimum size requirements, v-notching, and a prohibition on taking egg-bearing females to protect the resource, rather than direct controls on fishing effort or catch. However, in 2005 the Atlantic States Marine Fisheries Commission adopted a plan for the southern New England lobster management area (Area 2) that establishes a structure for limiting the number of license holders and the number of traps each lobsterman can have in the water. In this article, a bio-economic modeling exercise is employed to examine the biological and economic impacts of reductions to the level of fishing effort in a fishery that is modeled to represent the full-time lobster fishing fleet in Area 2. Model results show that a reduction in fishing effort has the potential to: ...

Comparing Historical Catch Rates of American Shad in Multifilament and Monofilament Nets: A Step toward Setting Restoration Targets for Virginia Stocks

AbstractRecreational and commercial harvest of American shad Alosa sapidissima in the Virginia waters of the Chesapeake Bay and its tributaries has been prohibited since 1994. The Atlantic States Marine Fisheries Commission Shad and River Herring Management Plan requires that Virginia develop restoration targets for its shad populations, but estimates of their sizes are not available and there is little information about historic population levels. Thus, establishing restoration targets based on population size is problematic. A current spawning stock monitoring program yields catch rate information that can be compared with historic catch rate information recorded in commercial fishery logbooks from the 1950s and the 1980s. However, multifilament gill nets were used in the 1950s and monofilament nets were used in the 1980s (as well as in the current monitoring program). A Latin square design was employed to test the differences in relative fishing power of the two gear types over 2 years of seasonal sampling on the York River, Virginia. Estimates are that the monofilament nets are roughly twice as efficient as the multifilament nets. Reported catch rates in the 1950s and 1980s are roughly equivalent. However, when adjustments are made for the differences in fishing gear, catch rates for the 1950s are twice as high as those during the 1980s. These results provide valuable information for setting restoration targets for Virginia stocks of American shad.

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

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.