Science Center for Marine Fisheries Archives - Page 3 of 8

Science Center for Marine Fisheries Enters New Five-Year NSF Partnership with Additional Funding

January 17, 2024 — The following was released by the Science Center for Marine Fisheries:

The Science Center for Marine Fisheries (SCEMFIS) begins 2024 by entering Phase III of the National Science Foundation’s Industry-University Cooperative Research Centers (IUCRC) Program. This new phase of NSF funding will allow SCEMFIS to further expand its mission of conducting innovative and in-demand marine science research, in cooperation with our fishing industry partners.

SCEMFIS is one of the many research centers in the NSF’s IUCRC program, which brings together leading academic researchers, and members of their collaborating industries, to identify and conduct needed scientific research. NSF provides funding for IUCRCs in five-year phases, with the Centers receiving more funding as they complete each phase and gain more industry members. The Centers that are able to make it to Phase III have exceptional levels of industry support and a proven track record of successful scientific research.

“Moving up to Phase III is a reflection on both the quality of research SCEMFIS regularly produces, and on the successful collaborative relationships that we have developed with our partners in the fishing industry,” said Dr. Eric Powell of the University of Southern Mississippi. “Entering this new phase will give us more resources to continue our mission to produce groundbreaking finfish and shellfish research, and engage in research, on the horizon, focusing on coexistence between commercial fishing and offshore wind development.”

In recent years, SCEMFIS researchers have published studies on finfish and shellfish resource constraints and opportunities, which have improved our scientific understanding of these key commercial species, and will help both the fishing industry and fishery managers ensure our fisheries remain sustainable. Studies have looked at how climate change has increased the growth rate of ocean quahogs, one of the longest-lived species in the ocean; how to reduce scientific uncertainty in managing Atlantic surfclams; and how to improve the accuracy of Atlantic menhaden assessments. The Center has also done acoustic survey work to locate previously uncounted adult menhaden schools during the winter.

In addition to its academic research, the Center has also dedicated its resources to providing NSF internship and research opportunities for many students, helping to develop the next generation of marine scientists who are interested in a future with food from the sea.

“Our partnership with SCEMFIS, over the past 10 years, has led to scientific research that has vastly expanded our members, and the public’s understanding of the commercial species we care most about and depend upon,” said Jeff Kaelin, representing Lund’s Fisheries as Chair of the SCEMFIS Industry Advisory Board. “This new five-year phase of funding will present us with even more opportunities to conduct the important research that will keep our fisheries productive and sustainable. We greatly appreciate the confidence that our NSF partners have in the work that our Center has accomplished over these past years.

Science Center for Marine Fisheries Supports Research Opportunities for Students

July 23, 2023 — The following was released by the Science Center for Marine Fisheries:

The Science Center for Marine Fisheries (SECMFIS) was founded to bring together industry and academia to support cutting-edge finfish and shellfish research. A critical element of this mission is to support the careers of students and up-and-coming scientists by actively involving them in Center-funded projects. That is why SCEMFIS member institutions are proud to provide research opportunities as part of the National Science Foundation’s Research Experiences for Undergraduates (REU) program.

The REU program allows students to participate directly in scientific research at the undergraduate level. This gives them valuable hands-on experience in the lab and in the field, lets them contribute to published studies, and helps lay the foundation for a future career in marine science. Many of our students who have successfully completed projects in the REU program have gone on to further their careers in academia and fisheries science and management.

SCEMFIS REU students have been integral in recent projects funded by the Center, conducting research on a range of topics, including geospatial analysis of cod spawning and how it is affected by climate change; the economic feasibility of Atlantic surfclam hatcheries; how potential offshore wind developments interact with existing ocean geography and nearby ocean species; improving clam dredge designs; the importance of forage fish in marine food webs, and research into the life history and population dynamics of surfclams and ocean quahogs.

The REU program has students at many SCEMFIS member institutions, including the University of Southern Mississippi, the Virginia Institute of Marine Science at William and Mary, Rutgers University, Nicholls State University, the University of Richmond, Carlton College, Michigan State University and the University of Texas, Austin.

“The future of the sciences depends on getting our students directly involved in research as often as possible, and the REU program has been a great way to accomplish that,” said Dr. Eric Powell of the University of Southern Mississippi. “Our REU students have contributed to some of the most important recent work done by the Center, and the Center has served as a great launching point for many scientific careers.”

Below, SCEMFIS would like to highlight some of our recent REU students, and the work that they have done for the Center:

Samantha Alaimo: Graduate Student at Rutgers University, New Brunswick, New Jersey

Samantha (Sam) Alaimo is a PhD student studying oceanography at Rutgers University under Dr. Josh Kohut. Working with Dr. Jeff Burst and his colleagues at the New Jersey Department of Environmental Protection, Sam hopes to better assess decadal and seasonal trends of frequently caught species compared to trends in oceanographic features, such as the Mid-Atlantic Cold Pool. Comparing fish abundance and biomass to changes in the cold pool over time would identify key environmental factors that influence fish distributions and allow for a baseline to be established prior to the construction of offshore wind.

Garrett Bellin: Undergraduate Student at William & Mary, Williamsburg, Virginia

Garrett Bellin is a rising sophomore at William & Mary studying applied statistics and data science. He is a researcher for the William & Mary Center for Geospatial Analysis, performing GIS analyses for various clients. Currently, he is working with Dr. Roger Mann using GIS mapping to find cod spawning locations and determine how they are affected by ocean warming trends. Using the DOPPIO and GLORYS ocean temperature datasets, ideal temperatures for cod spawning will be ascertained and overlaid with substrate and cod location data. Garrett hopes to be able to create GIS models that can predict future cod spawning grounds as ocean temperatures continue to rise. Policy changes could ultimately be affected which address the location and boundary of the Great South Channel Habitat Management Area near Nantucket.

Olivia Cohn: Undergraduate Student at William & Mary, Williamsburg, Virginia

Olivia (Livvie) Cohn is an undergraduate student veteran studying biology and marine science at William & Mary and is working with Dr. Roger Mann and Alex Marquardt as a Laboratory Technician in the VIMS Molluscan Ecology Lab. She has been assisting Alex in her PhD research by using image analysis to help track early growth and death rates of oyster spat. Livvie hopes to eventually take on individual research, gain more experience engaging with the local community, and fisheries management.

Caela Gilsinan: Undergraduate Student at William & Mary, Williamsburg, Virginia

Caela Gilsinan is an undergraduate at William & Mary and has been working on a wind energy/fisheries economy project with Dr. Andrew Scheld at the Virginia Institute of Marine Science. She has been able to meet with hatchery managers, researchers, and other experts in hatchery production, collecting information on production methods and costs, and developing a cost model to evaluate the economic viability of large-scale hatchery production for Atlantic surfclam. She developed skills in coding, simulation modeling, and analyzing techno-economic cost models to evaluate fixed, variable, and average production costs and maximum production scales.

Emily Gaudet: Undergraduate student at Nicholls State University, Thibodaux, Louisiana

Emily Gaudet is a undergraduate student at Nicholls State University majoring in Biology Pre-med. She is currently working with Dr. Whitaker as an REU student on a coastal predatory diet study. Emily is focusing on Speckled Trout Cynoscion nebulosus collected from all five coastal study areas in Louisiana. She is using sequencing to identify prey that in conventional diet studies might be labeled as unidentified with the hope of providing a more complete picture of the Speckled Trout diet.

Becca Horwitz: BS Degree (June 2022), Carlton College, Northfield, Minnesota

Becca has been working with Dr. Daphne Munroe and Dr. Travis Miles at the Rutgers University Department of Marine and Coastal Science for over a year. She has been exploring the overlap between the Mid-Atlantic Bight Cold Pool (a seasonally stratified coastal ocean feature) and proposed offshore wind lease areas in the Mid-Atlantic Bight region using the ocean model DOPPIO. After graduating from Carleton College in June, she joined Dr. Munroe’s lab to further explore the world of biological oceanography, as well as to continue her research. She is working on a paper that will hopefully be finished by spring 2023. Becca plans to apply for her PhD in a year after finishing her time with Dr. Munroe to continue studying the potential effects of offshore wind on the coastal environment.

Nathan Kennedy: Undergraduate Student at the University of Texas at Austin, Austin, Texas

Nathan Kennedy is a senior civil engineering major at the University of Texas at Austin. He is working with the Ocean Engineering Group at UT as an undergraduate research assistant, using CFD software to model and analyze the performance of a clam dredge. His focus lies in optimizing the design of the manifold by minimizing the energy losses of fluid flow through it, which he achieves by using programs like Fluent and Tecplot 360 to model the velocity and pressure distributions of various manifold designs.

Thais Lobo-Emond: Undergraduate Student at the University of Texas at Austin, Austin, Texas

Thais Lobo-Emond is a senior civil engineering student at the University of Texas at Austin. She has been working with the Ocean Engineering Group on Computational Fluid Dynamic modeling, under the supervision of Dr. Spyros Kinnas. In her position as an Undergraduate Research Assistant, Thais has learned to work with software such as Ansys, SolidWorks, and Fluent to model flows and analyze velocity, pressure, force, movements, and other flow characteristics. Thais has been using these software programs to improve the design of clam dredge jets for better overall performance.

Brett Renken: Undergraduate Student, University of West Florida, Pensacola, Florida

Brett Renken is from Oak Lawn, Illinois and is currently an undergraduate student at the University of West Florida, majoring in Marine Biology. He is working with Dr. Justine Whitaker as an REU student in the Coastal Genomics Lab at Nicholls State University. Brett’s project is part of a larger diet study and he is focusing on Spanish Mackerel Scomberomorus maculatus. He is performing dissections to remove gut contents, extracting DNA from the contents, and then sequencing to identify the contents to the lowest taxonomic level. He has also assisted with field work for other graduate students at Nicholls State, ranging from terrapin surveys at Grand Isle, Louisiana, collecting environmental DNA samples for mussel and fish species at sites in the Sabine and Calcasieu basins.

Ellen Rowe: Undergraduate Student at William & Mary, Williamsburg Virginia

Ellen Rowe is an undergraduate student studying biology and marine science at William & Mary. She is also involved with William & Mary’s Center for Geospatial Analysis. She has created communication materials for conservation work and scientific research experience using her knowledge of Geographic Information System (GIS). She is currently working with Dr. Roger Mann as an REU student at the Virginia Institute for Marine Science (VIMS). She will be looking at oyster survey data, finding ways to present and share this research effectively. She is excited to combine her interests in marine science, GIS, and science communication during her REU project.

Brody Phillips: Undergraduate Student at William & Mary, Williamsburg, Virginia

Brody is a first-generation undergraduate student at William & Mary majoring in biology and minoring in psychology. He is currently working with Dr. Roger Mann as a REU (Research Experiences for Undergraduates) student in the Virginia Institute of Marine Science (VIMS) Molluscan Ecology Lab to investigate the potential electromagnetic field (EMF) impacts of inter array cables from offshore wind farms on invertebrate species. This project consists of literature review of offshore wind farms, power cable modeling, and previously studied EMF relationships within the marine environment. While previous research in this area is minimal, predominant focus has been on more charismatic (vertebrate) species such as sharks, dolphins, and turtles. Almost no research related to underwater transmission cables and EMF alteration impacts at the neurological level has been done on invertebrate species. Along with literature review, he will be meeting with energy transmission engineers, neurophysiology researchers, and other professionals to determine the significance of these impacts and how they affect neuron communication and function in invertebrates.

Austin Sanchez: Undergraduate Student at the University of Texas at Austin, TX

Austin Sanchez is a second year Environmental Engineering student at the University of Texas, Austin. He has been working with the Ocean Engineering Group’s research team since his first year. My role is on the experimental side. He has been working on a project to optimize clam dredge jet speeds. As part of the project, he has helped design the clam dredge manifold and jets using 3D software, and has manufactured them on campus using 3D printers.

Rebecca Walsh: Undergraduate Student at the University of Richmond, Richmond, VA

Becca is an undergraduate at the University of Richmond studying biology, environmental studies, and geography. She spent the summer working with Dr. Robert Leaf at the University of Southern Mississippi Gulf Coast research lab, researching the caloric content of forage fish in the Gulf of Mexico. Through direct sampling, spatial, temporal, and age based trends of caloric content were investigated. Throughout the summer, she developed skills in sampling, new lab techniques, and coding. During the summer, she was also able to participate in NOAA SEAMAP ground fish survey. Becca is currently working on a paper remotely with Dr. Leaf and as part of her honors thesis that will be finished in spring 2023 when she graduates from Richmond.

Jasmine Whelan: BS Graduate, William & Mary, Williamsburg, Virginia

Jasmine received a B.S. in biology with a marine science minor from the College of William & Mary. Previously she worked in an avian lab where she studied the effect of mercury pollution and stress on a songbird’s ability to promote quality feather growth. As an REU recipient at VIMS, Jasmine worked in the Molluscan Ecology Lab assisting PhD student Alex Marquardt in her research on Virginia oyster life history.

Brynne Wisner: Undergraduate, Michigan State University, East Lansing, Michigan

Brynne Wisner is a senior at Michigan State University and has been working with Dr. Daphne Munroe at the Rutgers Haskin Shellfish Research Lab. She has been researching the age demographics of an Atlantic surfclam population with previously low abundance on the southern end of the Atlantic surfclam range. The results from this study will help determine current population stability and inform future fishing efforts. Brynne will be graduating this semester and hopes to continue to participate in fisheries research after graduation.

New surfclam study examines uncertainty, sustainability in surfclam management

April 6, 2023 — The following was released by the Science Center for Marine Fisheries:

Researchers with the Science Center for Marine Fisheries (SCEMFIS) are continuing their efforts to provide the latest and most up-to-date research on Atlantic surfclams, and to support the sustainable management of the surfclam fishery. A recently published study looks at how current surfclam management deals with uncertainty, and whether this uncertainty affects future sustainability.

The surfclam fishery is sustainably managed; it’s not overfished and overfishing is not occurring, nor have either of these issues arisen since the first fisheries management plan was adopted. The Mid-Atlantic Fishery Management Council (MAFMC) in collaboration with the surfclam fishery has implemented a conservative catch limit on the fishery, but significant uncertainty remains over some key estimates, such as the natural mortality rate and the spawning stock biomass, which measures the reproductive capacity of the surfclam population. Both are key indicators of the health of the stock. The study evaluates the likelihood that this conservative management strategy still could lead to unsustainable fishing.

The study, published in the Journal of Shellfish Research, uses a series of statistical simulations to model how uncertainty about the stock affects the risk that the stock may be overfished with current quotas in place; whether the current risk policy is appropriate; and the extent to which the future economic viability of the surfclam fishery is affected.

To do this, the study used the stock assessment models from the MAFMC’s surfclam assessment, and ran simulations with different values for natural mortality and the steepness of the stock-recruitment relationship, which measures how the rate of recruitment in a fished population reacts when the spawning stock is reduced. The study then examined whether any of the range of values used, when run through the assessment model, would lead to overfishing of the stock. This analysis also examined how harvest levels would affect surfclam density, a critical factor in maintaining a viable surfclam fishery.

Through these simulations, the study finds that the existing surfclam population is “robust to overfishing across a variety of management strategies,” and that “the surfclam stock is unlikely to become overfished or experience overfishing from currently implemented management strategies”.

Economically, the study found that “the fishery is not constrained by the current quota and unlikely to pursue fishing at such volumes that would decrease profit margins,” and the conservative quota cap adopted by the industry “has likely contributed to the sustainability of the Atlantic surfclam stock.”

While making these conclusions, the study also raised concerns about the effects of climate change on these estimates, and that the rapidly warming northwestern Atlantic may have a future impact on surfclam population dynamics. Because surfclams are highly sensitive to rising temperatures, this is a factor that may influence uncertainty in future assessments.

New funding to study shifting surf clams, potential fishing devaluation from offshore wind

January 4, 2022 — An effort to map changing surf clam habitat off the East Coast is among four new research projects to be funded in 2023 with $235,000 from the non-profit Science Center for Marine Fisheries (SCEMFIS).

SCEMFIS approved the funding at annual fall meeting, doling out an overall $109,000 increase in funding from the $126,000 the center approved for the 2022 funding year.

Projects are chosen for funding by members of the Center’s Industry Advisory Board, and with an eye to addressing the highest priorities in finfish and shellfish science. This year’s projects research new methods to chart the habitat overlap between ocean quahogs and surfclams; test better ways to analyze the diets of important predator species in the Gulf of Mexico; examine the financial impact of wind farm development on Northeast fisheries; and design a new, experimental clam dredge.

Clam resource distribution, a GIS summary: As the waters off the U.S. coast continue to warm, surf clams continue to move into deeper, formerly colder waters, causing an overlap in habitat with ocean quahogs, creating a problem for fishermen and regulators as two formerly separate fisheries begin to overlap.

This project funded at $19,719 and led by professor Roger Mann at the Virginia Institute for Marine Science, will develop GIS information charting this overlap using historical survey and fishing data, use temperature data to determine the influence of climate change over time, and use these data sets to project future surf clam migration.

Read the full article at the National Fisherman

Science Center for Marine Fisheries announces $230,000 in new research funding to start 2023

January 3, 2023 — The following was released by the Science Center for Marine Fisheries:

The Science Center for Marine Fisheries (SCEMFIS) has awarded $235,000 in new research funding for 2023. The funding, which covers four new projects, was approved by the Center at its annual fall meeting, and is a $109,000 increase in funding from the $126,000 approved by the Center in fall 2021.

These projects were chosen for funding by the members of the the Center’s Industry Advisory Board, and address some of the highest priorities in finfish and shellfish science. This year’s projects research new methods to chart the habitat overlap between ocean quahogs and surfclams; test better ways to analyze the diets of important predator species in the Gulf of Mexico; examine the financial impact of wind farm development on Northeast fisheries; and design a new, experimental clam dredge.

SCEMFIS is part of the National Science Foundation’s Industry-University Cooperative Research Centers program, and brings together researchers and academics in marine science with members of the fishing industry to identify and fund commercially important fisheries research.

The following research projects were approved for 2023:

Clam resource distribution, a GIS summary – As the waters off the U.S. coast continue to warm, surfclams continue to move into deeper, formerly colder waters, causing an overlap in habitat with ocean quahogs, creating a problem for fishermen and regulators as two formerly separate fisheries begin to overlap. This project, led by Dr. Roger Mann at the Virginia Institute for Marine Science, will develop GIS information charting this overlap using historical survey and fishing data, use temperature data to determine the influence of climate change over time, and use these data sets to project future surfclam migration ($19,719 in funding).
Metabarcoding the gut contents of predatory fish in coastal Louisiana – There is contradictory information available on the degree to which predator species in the Gulf of Mexico rely on various forage fish species, particularly Gulf menhaden. Current methods, which rely on analyzing stomach contents, have the potential to misidentify diets; techniques such as DNA sequencing is more likely to produce an accurate result. This study, led by Drs. Justine Whitaker and Chris Bonvillain of Nicholls State University, will collect DNA samples from selected stomach contents from Gulf fish, and analyze these DNA samples to correctly catalog the contents of the diets of these fish ($60,428 in funding).
Assessing stranded capital and capital devaluation in the seafood industry due to offshore wind energy development – Large-scale offshore wind power development is anticipated to negatively impact the commercial fishing industry. New wind farms in the Northeast will reduce fishable area and landings, impacting both upstream and downstream businesses in the seafood economy. This has the potential to devalue the physical capital used in seafood production, such as fishing vessels and shoreside processing infrastructure, which is often highly specialized and may have limited alternative uses. This project, led by Dr. Andrew Scheld at the Virginia Institute for Marine Science, will assess the potential for stranded capital and capital devaluation in the seafood industry by conducting a literature review, collecting information from a sample of seafood businesses to evaluate asset risk exposure, and developing models to assess exposure of vessel capital ($44,856 in funding).
A clam dredge with an integrated pump – One of the fundamental challenges in operating a hydraulic clam dredge is that, the deeper the dredge goes, the worse it will perform, due to the distance between the dredge on the sea floor and the dredge pump on the vessel. This project, led by Dr. Roger Mann of the Virginia Institute of Marine Science, will make a modified dredge design with the dredge pump on the dredge itself, and run comparison tests with a regular dredge to measure potential improvements ($110,000 in funding).

About SCEMFIS
SCEMFIS utilizes academic and fisheries resources to address urgent scientific problems limiting sustainable fisheries. SCEMFIS develops methods, analytical and survey tools, datasets, and analytical approaches to improve sustainability of fisheries and reduce uncertainty in biomass estimates. SCEMFIS university partners, University of Southern Mississippi (lead institution), and Virginia Institute of Marine Science, College of William and Mary, are the academic sites. Collaborating scientists who provide specific expertise in finfish, shellfish, and marine mammal research, come from a wide range of academic institutions including Old Dominion University, Rutgers University, University of Massachusetts-Dartmouth, University of Maryland, and University of Rhode Island.

The need for the diverse services that SCEMFIS can provide to industry continues to grow, which has prompted a steady increase in the number of fishing industry partners. These services include immediate access to science expertise for stock assessment issues, rapid response to research priorities, and representation on stock assessment working groups. Targeted research leads to improvements in data collection, survey design, analytical tools, assessment models, and other needs to reduce uncertainty in stock status and improve reference point goals.

Climate change impacting Atlantic shellfish, and scientists predict it will only get worse

July 25, 2022 — A team of researchers form the Science Center for Marine Fisheries, an organization with a number of partners and collaborating scientists from universities like the Virginia Institute of Marine Science, is examining how warmer waters will impact shellfish species harvested in the United States.

The research, centering on ocean quahogs and surfclams, is examining how the two species will begin to interact as changing ocean conditions cause the species to shift habitats. Ocean quahog are one of the longest-lived marine species in the world and inhabit cold waters in the Mid-Atlantic, while surfclams typically inhabit warmer areas.

Read the full article at SeafoodSource

Climate Change Creating New Conflicts for Surfclam, Ocean Quahog Fisheries as Warming Forces Habitat Shifts

July 21, 2022 — The following was released by the Science Center for Marine Fisheries:

Climate change is now affecting long-standing patterns for marine life, with warmer waters pushing species out of their traditional habitats and into newer areas. As these changes become increasingly common, they will create challenges for fishermen, scientists, and regulators. A team at the Science Center for Marine Fisheries (SCEMFIS) is examining the extent of the problem on two key shellfish species: surfclams and ocean quahogs.

Ocean quahogs, one of the longest-lived marine species on Earth, inhabit cold waters in the Mid-Atlantic; surfclams, in contrast, have traditionally inhabited warmer areas. With climate change, surfclams’ traditional habitats have become some of the fastest-warming waters in the region, forcing them to move north into the colder waters traditionally occupied by quahogs.

“The area of overlap is getting potentially larger and larger as the Middle Atlantic warms, because one species is moving in, and the other one hasn’t quite got the message and moved out yet,” said Dr. Roger Mann of the Virginia Institute of Marine Science, one of the lead scientists on the survey.

In the fall of 2021, a team from SCEMFIS partnered with an industry fishing vessel, the F/V Pursuit, to document the extent of this habitat overlap. They took samples in several areas, working through surfclam and ocean quahog habitats, as well as areas of intermingling in between. The team documented what was caught, its species, size, age, and location.

After analyzing the data, the team found significant habitat overlap and intermixing between surfclams and ocean quahogs, much more than was expected at the start of the survey.

“One of the surprises though was just how extensive the overlap is now,” said Dr. Eric Powell, of the University of Southern Mississippi, another one of the survey’s lead scientists. “This is a major community shift on the continental shelf and it’s something that the management agencies and the fishery are going to have to get their arms around and deal with.”

Intermixing of ocean quahogs and surfclams is just the latest example of how climate change is creating new problems for fishermen. Under current rules, fishermen are not allowed to harvest clams and quahogs at the same time. In an environment where these species inhabited separate parts of the ocean, these rules were easy for fishermen to comply with. But climate-influenced migration is making harvesting these species much more challenging, a problem that will only increase in importance as trends continue.

“As bad as it is, it’s going to be much worse in five years, in my opinion,” said Dr. Powell. “The challenge, both to the fishery and management, is to figure out how to revise the regulations so both of these species can be landed without causing a problem with the inherent stability of the fishery and management.”

“The information that we get is vitally important to us staying not only a sustainable fishery, but also a fishery in good stead with enforcement,” said Guy Simmons, Senior Vice President at Sea Watch International, which harvests clams and is a member of the SCEMFIS Industry Advisory Board.

New Study Develops Method to Age Ocean Quahog, Longest-Lived Species in the Ocean

April 21, 2022 — The following was released by the Science Center for Marine Fisheries:

Ocean quahogs are some of the longest-lived animals in the world, with the oldest specimens in the U.S. Mid-Atlantic regularly recorded at over 200 years old. But even though they are famous for their longevity, many details about the age structure of ocean quahogs—such as how it affects estimates of recruitment, biomass, and growth—are still not well understood. A newly published study finds that ocean quahogs have recruited continuously for over 200 years on Georges Bank, off the East Coast of the U.S., while also providing new tools to researchers and fisheries managers to better understand the species.

Funded by the Science Center for Marine Fisheries (SCEMFIS), the study collected a large sample of ocean quahogs—gathering over 600 specimens—and recorded relevant information on them, including age, length, and sex. Researchers then took that information to develop what’s known as an “age-length key,” which charts the probability of an animal of a given age being a specific length. The key can be used to determine the distribution of ages in a population based on the simple determination of the distribution of lengths.

Currently, ocean quahog models used for management are based on the length of the ocean quahog, rather than its age. Like trees, ocean quahogs can be aged by counting the growth rings that form over time, in this case on its outer shell. But because the process of directly determining an individual ocean quahog’s age is time-consuming and impractical for most larger surveys, length has been used instead as a proxy for age.

The age-length key resulting from this study, given the size of the sample of ocean quahogs collected, is a robust data set that can be consulted to quickly estimate ages of thousands of quahogs using only animal lengths. A reliable age-length key improves the potential to introduce more age-based data into ocean quahog management, making it more consistent with how other species are managed.

“Because ocean quahogs are so long-lived, getting a method to quickly and accurately estimate their age is critically important,” said Kathleen Hemeon, of the Gulf Coast Research Laboratory and one of the authors of the study, which was published in the Journal of the Marine Biological Association of the United Kingdom. “Having this kind of age and length data available can help change the way we manage the species.”

In addition to developing a more comprehensive age-length key, the study had other notable findings that are important in furthering our understanding of ocean quahogs. In the ocean quahogs sampled, the study confirmed that ocean quahogs are a sexually dimorphic species, with female ocean quahogs generally larger than males. It also found that recruitment, or the number of new ocean quahogs that are successfully born into the population every year, has been an annual occurrence since the late 1800s, which is notable given their long lifespans and suspected delayed maturity. In its sampling, the study collected the oldest ocean quahog on record in Massachusetts, at 261 years old.

“This study addresses a conundrum that has bedeviled quahog fishery managers for many years – namely, whether recruitment occurs consistently, or only sporadically in cycles some thirty years apart,” said Tom Alspach, of Sea Watch International, a seafood company based in Maryland. “This evidence of consistent annual recruitment can remove a level of uncertainty from management decision-making, leading to greater confidence in more generous quota setting, with a direct positive impact on industry.”

About SCEMFIS

SCEMFIS utilizes academic and fisheries resources to address urgent scientific problems limiting sustainable fisheries. SCEMFIS develops methods, analytical and survey tools, datasets, and analytical approaches to improve sustainability of fisheries and reduce uncertainty in biomass estimates. SCEMFIS university partners, University of Southern Mississippi (lead institution), and Virginia Institute of Marine Science, College of William and Mary, are the academic sites. Collaborating scientists who provide specific expertise in finfish, shellfish, and marine mammal research, come from a wide range of academic institutions including Old Dominion University, Rutgers University, University of Massachusetts-Dartmouth, University of Maryland, and University of Rhode Island.

New study offers improvements to estimating shellfish populations

March 14, 2022 — The following was released by the Science Center for Marine Fisheries:

A new study, jointly conducted and funded by the Science Center for Marine Fisheries (SCEMFIS) and the National Marine Fisheries Service (NMFS), finds ways to reduce a source of uncertainty in the Atlantic surfclam and ocean quahog population estimates: defining the efficiency of the survey gear. The study, published in Fishery Bulletin, is part of the Center’s long-running efforts to improve our understanding of shellfish.

The dredge efficiency issue, which dates to the early 1990s, is about how effective clam research survey vessels are at catching surfclams and ocean quahogs. The efficiency of a clam dredge—which is a measure of the proportion of Atlantic surfclams or ocean quahogs on the ocean floor that a dredge can catch—is one of the key variables in stock assessment population estimates. The efficiency of the dredge is a primary factor affecting the biomass estimate of the stock and therefore an important criterion determining how the assessment evaluates the status of the stock relative to management goals.

One way researchers measure efficiency is through field depletion experiments, where a dredge is run multiple times in a single area to measure the percentage of available shellfish it caught with each tow. These experiments are used in both the Atlantic surfclam and ocean quahog assessments to help estimate their dredge efficiencies. There is no way to know what true dredge efficiency is, but conducting many depletion experiments allows scientists to make a reasonable estimate.

The first depletion experiment was conducted in 1997 as a joint effort between NMFS, academic scientists, and the clam fishery. This team carried out many such studies over the following 15 years, making this one of the longest running successful collaborations of this type. This recent study addresses the remaining uncertainty surrounding dredge efficiency by looking at data from this large set of depletion experiments conducted over two decades and examines the quality of these experiments and the efficiency estimates they produced. Specifically, the study took a close look at simulated depletion experiments, where scientists know what the true dredge efficiency is, to identify common characteristics of studies that do a good job estimating dredge efficiency compared to those that do a poor job.

By focusing on the “best” experiments and identifying field experiments that potentially produced inaccurate efficiency estimates, scientists can refine the set of depletion studies used to help estimate efficiency in stock assessments. This refined set of depletion studies has particular influence on non-model-based biomass estimates, which play an important role in verifying the model-based results and are commonly used in management. Once identified, characteristics of good and bad depletion experiments can also inform methodology used in future experiments.

“Identifying field depletion experiments with accurate efficiency estimates helps confirm present stock assessment models’ gear efficiency estimates,” said Leanne Poussard, of the University of Southern Mississippi’s Gulf Coast Research Laboratory and the lead author of the study.

“Ms. Poussard’s work has rekindled interest in the cooperative depletion experiment dataset and produced important guidance for anyone undertaking similar experiments in the future”, said Dr. Dan Hennen of NMFS.

SCEMFIS: New Survey Will Help Fill Gaps in Menhaden Count in New England, Mid-Atlantic

January 14, 2022 — The Science Center for Marine Fisheries (SCEMFIS) highlighted a new project that will look to count a population of menhaden that could help inform not only a local New Jersey fishery but other fisheries in New England and the Mid-Atlantic region.

A team from the University of Maryland Center for Environmental Science’s (UMCES) Chesapeake Biological Laboratory and the Virginia Institute of Marine Science, in collaboration with NOAA Fisheries are on the verge of launching a winter population survey of menhaden, specifically off the coast of New Jersey, SCEMFIS said.

That area is home to a growing winter bait fishery but because there hasn’t been much work to survey the population that far north, there is not a strong enough count of how many fish are in that area.

The survey, which will launch from Cape May, New Jersey, will use sonar equipment to estimate the number of menhaden schooling in the area, and will collect additional information to estimate age, size, and weight, data that will be important for managing the fishery, per SCEMFIS.

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