Janet A. Nye, a master’s student in marine biology-biochemistry in the University of Delaware Graduate College of Marine Studies (CMS), is the recipient of the fourth annual scholarship from the Delaware Mobile Surf Fishermen. Under the guidance of Dr. Timothy Targett, professor of marine biology-biochemistry, Nye will use the $1,000 scholarship to support her thesis research on how changes in population size affect reproductive characteristics of the weakfish, Cynoscion regalis.
The weakfish is Delaware’s state fish and has been an important fishery in the Delaware Bay since the 1800s. In the late 1980s and early 1990s, the species was overfished and the population declined. Strict fishing regulations were imposed, and although the fishery has rebounded somewhat since that time, very large weakfish are still not as abundant as they were in the early 1980s.
In many overexploited species, the remaining fish grow faster because there is more food available. This faster growth triggers the fish to reach sexual maturity at an earlier age and a smaller size. These younger and smaller fish may partially compensate for the reproductive capacity lost from larger fish that have been removed from the fishery.
These smaller fish often produce fewer and smaller eggs than larger, older fish. Smaller eggs often yield smaller larvae, which may die before contributing to the fishery. A knowledge of how reproductive characteristics (such as age and size at maturity, the number of eggs produced by one fish in one spawn, spawning frequency, and the average number of eggs produced by one fish over the entire spawning season) are affected by changes in the weakfish population is important to effectively manage the fishery.
“If management efforts do not take into account how the size of the population may affect reproductive characteristics, then the ability of the weakfish stock to recover may either be over- or underestimated,” says Nye, a native of Charlotte, North Carolina. “Overestimating the potential for stock recovery puts the weakfish fishery at risk of crashing, whereas underestimating it prevents the resource to be fished to its full potential. My data will help us understand the relationship between stock size and reproductive output, which will assist management agencies in maintaining the population and health of the fishery.”
Management of the weakfish fishery currently is based on studies that assume the reproductive characteristics do not change with population size. In addition, these studies were done in the early 1990s when the population was extremely low. The population has increased substantially since that time. Nye’s studies will provide valuable information about the reproductive characteristics when the weakfish population is high.
“I am very excited about receiving the scholarship,” says Nye. “The relationship between population size and reproductive characteristics is important in guiding management efforts that will enhance and protect the weakfish fishery. I will use the scholarship funds to purchase equipment and supplies that are needed to complete my study.”
The Delaware Mobile Surf Fishermen is a group of individuals dedicated to maintaining sport fisheries in Delaware. Since 1998, the group has awarded a scholarship to a qualified student in the Graduate College of Marine Studies. “We believe the scholarship is an important way to support the research that is being conducted in the Delaware Bay,” says Dr. Ann Hastings, chair of the fishing group’s Subcommittee on Scholarships. “The research provides valuable information that will ensure that our marine animals and plants will continue to thrive in years to come.”