Who We Are
The Fishery Biology Program is located at the Woods Hole Massachusetts Laboratory of the National Marine Fisheries Service (NMFS), Northeast Fisheries Science Center (NEFSC). We are one of three programs in the Population Biology Branch of the Fisheries and Ecosystems Monitoring and Analysis Division.Front Row (Seated):The group was established in 1965 as the Age and Growth Unit. The Unit was initially responsible for performing routine age determinations for haddock, Melanogrammus aeglefinus, and yellowtail flounder, Limanda ferruginea, from the waters of the northwest Atlantic Ocean off the coast of the United States. During this time, and through the 1970s, validation studies were carried out, new sample processing and aging techniques were developed, and many other species were added to the list. The Age and Growth Unit gradually evolved into a group that studies not only fish growth, but basic biology of fish and shellfish. In 1978, the Unit's name was changed to the Fishery Biology Investigation and then Program in 1998 to reflect the changes in its responsibilities and the Center's organization, however, we are still often refered to as "Age and Growth".
Current Staff
Kathy Lang, Research Fishery Biologist
Nancy Munroe, Biological Science Laboratory Technician (Fisheries)
Daphne Cassidy, Biological Science Laboratory Technician (Fisheries)
Second Row (Seated):
Sandy Sutherland, Fishery Biologist
Blanche Jackson, Biological Science Laboratory Technician (Fisheries)
Grace Thornton, Biological Science Laboratory Technician (Fisheries)
Third Row (Standing):
Nina Shepherd, Biological Science Laboratory Technician (Fisheries)
Bill Duffy, Biological Science Laboratory Technician (Fisheries)
Sarah Pregracke, Biological Science Laboratory Technician (Fisheries)
John "Jay" Burnett, Research Fishery Biologist, Program Chief
Liz O'Neil, Biological Science Laboratory Technician (Fisheries)
What We Do
The mission of the Fishery Biology Program is to quantify fundamental demographic characteristics of marine fish and invertebrate populations. Those results are used in stock assessment analyses, in models designed to guide management decisions, and related research. The Program focuses on basic biological processes (particularly growth and reproduction) which are essential to understanding the population dynamics of exploited stocks.Our current approach is to:
The Fishery Biology Program ages about 35-50,000 fish per year. We age 18 species (26 stocks) of fish and shellfish from samples collected during research vessel surveys and 14 species (21 stocks) from the commercial fishery.
- Compile data and develop information relative to fish and shellfish growth and maturation
- Validate aging methods and develop and improve aging techniques
- Support age structure exchanges and aging workshops to ensure comparability between age readers, both within and between labs
Click here for a list of species we age and the structures we use to age them
Click
here to read about our new and improved sectioning technique
Click here for the Templates for Calculating Aging Precision
How We Age Fish
The choice of an age determination method for a given species involves deciding on an appropriate aging structure (scales, otoliths, vertebrae, spines, etc.) and processing method (impressions, thin sections, etc.) for that structure. The next step is validation, in which the marks used to age fish are verified to occur once per year and at approximately the same time each year. Common validation techniques include direct methods such as tag/recapture studies, including marking with chemicals such as oxytetracycline, calcein, and others; and indirect techniques such as back-calculation, marginal increment analysis, edge progression analysis, length frequency-year class progression analysis, radiometric/isotope analysis, elemental analysis, and others.To age a fish, an age reader must identify the annual growth marks (annuli) on the structure chosen. In temperate waters, fish growth is fast during the summer months when water temperatures are warm, and slow during the cold winter months. A year of growth is defined as one summer zone plus one winter zone. These zones are identified on scales as areas of wide (summer) and narrow (winter) circulus spacing. On otoliths, these zones are identified as alternating opaque and translucent bands when viewed microscopically.
In 1988, the Fishery Biology Program developed and published a set of detailed descriptions of the age determination methods we routinely use. These descriptions are being updated and will be reprinted here in their entirety. The descriptions are designed for use primarily by fishery biologists and professional age readers and students but may be of general interest.
Why We Age Fish
Basic biological data are the foundation on which all assessments of fisheries resources are built. These include parameters such as the size and age composition of the population and catch (both landed and discarded), growth rates, and maturation. The most thorough assessments include age specific estimates of stock biomass, mortality rates, and predictions of future stock conditions. These require knowledge of the size and age composition of the catch and indices of relative abundance by age. Rates of growth, mortality (due to natural causes and fishing), and reproduction can only be calculated if changes in maturity or size (and numbers) at age can be monitored over time. Fish age is also a critical correlate to many biological and pathological processes.
What Is Done With Our Age Data
The NEFSC collects samples from three primary sources. In order to obtain unbiased estimates of the age composition of a fish population, samples from research vessel surveys are analyzed. These surveys are generally conducted four times each year in order to monitor the abundance and to follow the seasonal progression of growth and maturation of most species inhabiting the waters off the northeast coast of the United States.Samples are also collected from commercial and recreational fisheries in order to estimate the age composition of the removals from the population. These samples are collected from the docks (the landed portion of the catch) and directly from fishing vessels (to estimate the age composition of the discarded portion of the catch).
Age and length data are then utilized in models that allow assessment scientists to estimate the biomass of fish and shellfish populations at age and to examine the potential effects of continuing removals from those populations. The Resource Evaluation and Assessment Division of the NEFSC publishes annual updates of the assessments of the fish and shellfish resources off the northeast coast of the United States. The document also includes descriptions of the methods used to analyze fish populations. If you are interested in viewing this document to learn more about assessment methods used at the NEFSC or the status of a particular species click here.
Recent Staff Reports and Publications
For further information about the FBP, contact Jay Burnett via e-mail or write to:
Fishery Biology Program
NOAA - National Marine Fisheries Service
Northeast Fisheries Science Center
166 Water Street
Woods Hole, Massachusetts 02543-1097
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