American FisheriesSociety143rd Annual Meeting
September 8-12, 2013
Little Rock, Arkansas
Ellen K. Pikitch: “Forage Fish: A Crucial Link in Aquatic Ecosystems,” Sept. 11, 8 a.m.
Forage fish play a pivotal role in marine ecosystems and economies worldwide by sustaining many predators and fisheries directly and indirectly. The Lenfest Forage Fish Task Force conducted the most comprehensive global analysis of the science and management of forage fish populations to date. This group of 13 pre-eminent scientists used a variety of approaches, including workshops, site visits, a series of nine case studies, review of existing theory and practice, and two quantitative analyses using marine food web models. In the first of these quantitative studies, the task force estimated global forage fish contributions to marine ecosystems through a synthesis of 72 published Ecopath models from around the world. The global catch value of forage fisheries was $5.6 billion, whereas fisheries supported by forage fish were more than twice as valuable ($11.3 billion). In the second quantitative study, the task force used 10 Ecopath with Ecosim models to simulate the effects of various fishing strategies on forage fish and their predators. It found that fishing at FMSY increases the risk of forage fish population collapse seven-fold and more than doubles the average decline in predator populations, relative to a “hockey stick” strategy with fishing mortality limited to 50 percent of FMSY at B0 and declining to zero at or below 40 percent of B0. The task force recommends employing the latter strategy for forage fisheries where sufficient information exists about the target species and its role in marine ecosystems. It also recommends that no new forage fisheries be initiated in low-information situations, whereas more aggressive fishing strategies might be appropriate in data-rich circumstances. This presentation will briefly review the recommendations of the Lenfest Forage Fish Task Force and their rationale, and provide an update on the implementation of these recommendations to date.
Konstantine Rountos: “The Effects of Harmful Algal Blooms on Early Life Stages of Estuarine Forage Fish,”
Sept. 11, 1:20 p.m.
(Co-Authors: Ying Zhong Tang , Christopher J. Gobler, Ellen K. Pikitch)
Harmful algal blooms (HABs) caused by the dinoflagellate, Cochlodinium polykrikoides, have increased in geographic extent, frequency, and duration in many coastal areas worldwide. These blooms have negatively impacted many coastal fisheries, causing mass mortalities to both wild and farmed fish. While these mortalities have been well documented for juvenile and adult fish, the potential impacts to early life stages (i.e. embryos and eleutheroembryos) have not been explored. The potential toxicity of HABs on early life stages could significantly affect recruitment in coastal fish populations. To address this critical research gap, we conducted a series of toxicity experiments using clonal cultures of C. polykrikoides and early life stages of three forage fish species (Menidia menidia, Menidia beryllina, and Cyprinodon variegatus), all common in Northeast U.S. estuaries. We present the impacts of C. polykrikoides on embryo survival and hatching success as well as the survival of newly hatched eleutheroembryos. This research provides the first evidence of toxicity by C. polykrikoides to early life stage fish and advances our understanding of the potential ecosystem impacts of this HAB.
Konstantine Rountos: “Insights From a Bay On the Brink” (Poster Presentation), Sept. 9.
(Co-Authors: Kristin Broms, Ellen K. Pikitch)
Shinnecock Bay is a New York estuary that was once considered pristine, supporting robust shellfish and recreational finfish fisheries. Over the last several decades, water quality has deteriorated, and the Bay has experienced collapsed fish and shellfish populations, the steady decline of seagrass habitat, and the onset of three harmful algal bloom species. These aspects present a challenging reality for the future of the Bay. In response to this crisis, the Shinnecock Bay Restoration Program has been created to restore water quality, seagrass habitat and shellfish populations in the Bay. We present the results from two years of benthic trawling research in both the eastern and western portions of the Bay. Marginally significant differences in catch per unit effort (CPUE) of recreationally important fish species were found, with higher CPUE in the pristine eastern portion of the Bay. Shellfish predators, including the blue crab (Callinectes sapidus) and mud crab (Family: Xanthidae) species were commonly caught bay-wide and there were no significant differences in their CPUE between bay side and habitat type. This survey research provides important baseline data on fish and crab populations in the Bay, which can inform ongoing and future shellfish restoration work and monitoring.