Application of an acoustic–trawl survey design to improve estimates of rockfish biomass

Biomass estimates of several species of Alaskan rockfishes exhibit large interannual variations. Because rockfishes are long lived and relatively slow growing, large, short-term shifts in population abundance are not likely. We attribute the variations in biomass estimates to the high variability in the spatial distribution of rockfishes that is not well accounted for by the survey design currently used. We evaluated the performance of an experimental survey design, the Trawl and Acoustic Presence/Absence Survey (TAPAS), to reduce the variability in estimated biomass for Pacific ocean perch (Sebastes alutus). Analysis of archived acoustic backscatter data produced an acoustic threshold for delineating potential areas of high (“patch”) and low (“background”) catch per unit of effort (CPUE) in real time. In 2009, we conducted a 12-day TAPAS near Yakutat, Alaska. We completed 59 trawls at 19 patch stations and 40 background stations. The design performed well logistically, and Pacific ocean perch (POP) accounted for 55% of the 31 metric tons (t) of the catch from this survey. The resulting estimates of rockfish biomass were slightly less precise than estimates from simple random sampling. This difference in precision was due to the weak relationship of CPUE to mean volume backscattering and the relatively low variability of POP CPUE encountered. When the data were re-analyzed with a higher acoustic threshold than the one used in the field study, performance was slightly better with this revised design than with the original field design. The TAPAS design could be made more effective by establishing a stronger link between acoustic backscatter and CPUE and by deriving an acoustic threshold that allows better identification of backscatter as that from the target species.

In search of climate effects on Atlantic Croaker (Micropogonias undulatus) stock off the U.S. Atlantic coast with Bayesian state-space biomass dynamic models

Atlantic Croaker (Micropogonias undulatus) production dynamics along the U.S. Atlantic coast are regulated by fishing and winter water temperature. Stakeholders for this resource have recommended investigating the effects of climate covariates in assessment models. This study used state-space biomass dynamic models without (model 1) and with (model 2) the minimum winter estuarine temperature (MWET) to examine MWET effects on Atlantic Croaker population dynamics during 1972–2008. In model 2, MWET was introduced into the intrinsic rate of population increase (r). For both models, a prior probability distribution (prior) was constructed for r or a scaling parameter (r0); imputs were the fishery removals, and fall biomass indices developed by using data from the Multispecies Bottom Trawl Survey of the Northeast Fisheries Science Center, National Marine Fisheries Service, and the Coastal Trawl Survey of the Southeast Area Monitoring and Assessment Program. Model sensitivity runs incorporated a uniform (0.01,1.5) prior for r or r0 and bycatch data from the shrimp-trawl fishery. All model variants produced similar results and therefore supported the conclusion of low risk of overfishing for the Atlantic Croaker stock in the 2000s. However, the data statistically supported only model 1 and its configuration that included the shrimp-trawl fishery bycatch. The process errors of these models showed slightly positive and significant correlations with MWET, indicating that warmer winters would enhance Atlantic Croaker biomass production. Inconclusive, somewhat conflicting results indicate that biomass dynamic models should not integrate MWET, pending, perhaps, accumulation of longer time series of the variables controlling the production dynamics of Atlantic Croaker, preferably including winter-induced estimates of Atlantic Croaker kills.

Our living oceans: report on the status of U.S. living marine resources, 6th edition

The National Marine Fisheries Service (NMFS) is dedicated to the stewardship of living marine resources (LMR’s). This is accomplished through science-based conservation and management, and the promotion of healthy ecosystems. As a steward, NMFS has an obligation to conserve, protect, and manage these resources in a way that ensures their continuation as functioning components of healthy marine ecosystems, affords economic opportunities, and enhances the quality of life for the American public. In addition to its responsibilities within the U.S. Exclusive Economic Zone (EEZ), NMFS plays a supportive and advisory role in the management of LMR’s in the coastal areas under state jurisdiction and provides scientific and policy leadership in the international arena. NMFS also implements international measures for the conservation and management of LMR’s, as appropriate.NMFS receives its stewardship responsibilities under a number of Federal laws. These include the Nation’s primary fisheries law, the Magnuson Fishery Conservation and Management Act. This law was first passed in 1976, later reauthorized as the Magnuson-Stevens Fishery Conservation and Management Act in 1996, and reauthorized again on 12 January 2007 as the Magnuson-Stevens Fishery Conservation and Management Reauthorization Act (MSRA). The MSRA mandates strong action to conserve and manage fishery resources and requires NMFS to end overfishing by 2010 in all U.S. commercial and recreational fisheries, rebuild all overfished stocks, and conserve essential fish habitat.

Characterization of toxic impacts on living marine resources in tidal rivers of the Chesapeake Bay

In 1999, the Chesapeake Bay Program completed a survey of existing data on chemical contaminants and the potential for bioeffects in 38 tidal river systems of Chesapeake Bay. This review led to the identification of 20 areas for which there were insufficient data to adequately characterize the potential for contaminant bioeffects on the Bay’s living resources. The goal of the present study was to estimate the current status of ecological condition in five of these areas and thus help to complete the overall toxics inventory for the Bay. These five systems included the Chester River, Nanticoke River, Pocomoke River, Lower Mobjack Bay (Poquosin and Back Rivers) and the South and Rhode Rivers. This study utilized a Sediment Quality Triad (SQT) approach in combination with additional water-column contaminant analysis to allow for a “weight of evidence” assessment of environmental condition. A total of 60 stations distributed among the five systems, using a probabilistic stratified random design, were sampled during the summer of 2004 to allow for synoptic measures of sediment contamination, sediment toxicity, and benthic condition. Upon completion of all analyses, stations were assigned to one of four categories based on the three legs of the triad. Stations with high sediment quality had no hits on any of the three legs of the triad; those with moderate quality had one hit; those with marginal quality had two hits; and those with poor quality had hits for all three legs of the triad. The Pocomoke River had by far the largest proportion of the total area (97.5%) classified as having high sediment quality, while the Rhode/South system had the highest proportion (11.4%) classified as poor. None of the stations in the Chester River, Nanticoke River, and Lower Mobjack Bay systems were classified as poor. More than 65% of the area of each of the five systems was classified with high to moderate sediment quality. The Rhode/South system had 30.4% of total area classified with marginally to severely poor quality. The results of this study highlight the importance of using multiple indicators and a “weight of evidence” approach to characterize environmental quality and the potential bioeffects of toxic contaminants.

The potential consequences of climate variability and change on coastal areas and marine resources: report of the Coastal Areas and Marine Resources Sector Team, U.S. National Assessment of the Potential Consequences of Climate Variability and Change, U.S. Global Change Research Program

Coastal and marine ecosystems support diverse and important fisheries throughout the nation’s waters, hold vast storehouses of biological diversity, and provide unparalleled recreational opportunities. Some 53% of the total U.S. population live on the 17% of land in the coastal zone, and these areas become more crowded every year. Demands on coastal and marine resources are rapidly increasing, and as coastal areas become more developed, the vulnerability of human settlements to hurricanes, storm surges, and flooding events also increases. Coastal and marine environments are intrinsically linked to climate in many ways. The ocean is an important distributor of the planet’s heat, and this distribution could be strongly influenced by changes in global climate over the 21st century. Sea-level rise is projected to accelerate during the 21st century, with dramatic impacts in low-lying regions where subsidence and erosion problems already exist. Many other impacts of climate change on the oceans are difficult to project, such as the effects on ocean temperatures and precipitation patterns, although the potential consequences of various changes can be assessed to a degree. In other instances, research is demonstrating that global changes may already be significantly impacting marine ecosystems, such as the impact of increasing nitrogen on coastal waters and the direct effect of increasing carbon dioxide on coral reefs. Coastal erosion is already a widespread problem in much of the country and has significant impacts on undeveloped shorelines as well as on coastal development and infrastructure. Along the Pacific Coast, cycles of beach and cliff erosion have been linked to El Niño events that elevate average sea levels over the short term and alter storm tracks that affect erosion and wave damage along the coastline. These impacts will be exacerbated by long-term sea-level rise. Atlantic and Gulf coastlines are especially vulnerable to long-term sea-level rise as well as any increase in the frequency of storm surges or hurricanes. Most erosion events here are the result of storms and extreme events, and the slope of these areas is so gentle that a small rise in sea level produces a large inland shift of the shoreline. When buildings, roads and seawalls block this natural migration, the beaches and shorelines erode, threatening property and infrastructure as well as coastal ecosystems.

Economic valuation of natural resources: a handbook for coastal resource policymakers

Professionals who are responsible for coastal environmental and natural resource planning and management have a need to become conversant with new concepts designed to provide quantitative measures of the environmental benefits of natural resources. These amenities range from beaches to wetlands to clean water and other assets that normally are not bought and sold in everyday markets. At all levels of government — from federal agencies to townships and counties — decisionmakers are being asked to account for the costs and benefits of proposed actions. To non-specialists, the tools of professional economists are often poorly understood and sometimes inappropriate for the problem at hand. This handbook is intended to bridge this gap. The most widely used organizing tool for dealing with natural and environmental resource choices is benefit-cost analysis — it offers a convenient way to carefully identify and array, quantitatively if possible, the major costs, benefits, and consequences of a proposed policy or regulation. The major strength of benefit-cost analysis is not necessarily the predicted outcome, which depends upon assumptions and techniques, but the process itself, which forces an approach to decision-making that is based largely on rigorous and quantitative reasoning. However, a major shortfall of benefit-cost analysis has been the difficulty of quantifying both benefits and costs of actions that impact environmental assets not normally, nor even regularly, bought and sold in markets. Failure to account for these assets, to omit them from the benefit-cost equation, could seriously bias decisionmaking, often to the detriment of the environment. Economists and other social scientists have put a great deal of effort into addressing this shortcoming by developing techniques to quantify these non-market benefits. The major focus of this handbook is on introducing and illustrating concepts of environmental valuation, among them Travel Cost models and Contingent Valuation. These concepts, combined with advances in natural sciences that allow us to better understand how changes in the natural environment influence human behavior, aim to address some of the more serious shortcomings in the application of economic analysis to natural resource and environmental management and policy analysis. Because the handbook is intended for non-economists, it addresses basic concepts of economic value such as willingness-to-pay and other tools often used in decision making such as costeffectiveness analysis, economic impact analysis, and sustainable development. A number of regionally oriented case studies are included to illustrate the practical application of these concepts and techniques.

A baseline assessment of the ecological resources of Jobos Bay, Puerto Rico

This baseline assessment of Jobos Bay and surrounding marine ecosystems consists of a two part series. The first report (Zitello et al., 2008) described the characteristics of the Bay and its watershed, including modeling work related to nutrients and sediment fluxes, based on existing data. The second portion of this assessment, presented in this document, presents the results of new field studies conducted to fill data gaps identified in previous studies, to provide a more complete characterization of Jobos Bay and the surrounding coral reef ecosystems. Specifically, the objective was to establish baseline values for the distribution of habitats, nutrients, contaminants, fi sh, and benthic communities. This baseline assessment is the first step in evaluating the effectiveness in changes in best management practices in the watershed. This baseline assessment is part of the Conservation Effects Assessment Project (CEAP), which is a multi-agency effort to quantify the environmental benefits of conservation practices used by agricultural producers participating in selected U.S. Department of Agriculture (USDA) conservation programs. Partners in the CEAP Jobos Bay Special Emphasis Watershed (SEW) included USDA’s Agricultural Research Service (ARS) and the Natural Resources Conservation Service (NRCS), National Oceanic and Atmospheric Administration (NOAA) and the Government of Puerto Rico. The project originated from an on-going collaboration between USDA and NOAA on the U.S. Coral Reef Task Force. The Jobos Bay watershed was chosen because the predominant land use is agriculture, including agricultural lands adjacent to the Jobos Bay National Estuarine Research Reserve (JBNERR or Reserve), one of NOAA’s 26 National Estuarine Research Reserves (NERR). This report is organized into six chapters that represent a suite of interrelated studies. Chapter 1 provides a short introduction to Jobos Bay, including the land use and hydrology of the watershed. Chapter 2 is focused on benthic mapping and provides the methods and results of newly created benthic maps for Jobos Bay and the surrounding coral reef ecosystem. Chapter 3 presents the results of new surveys of fish, marine debris, and reef communities of the system. Chapter 4 is focused on the distribution of chemical contaminants in sediments within the Bay and corals outside of the Bay. Chapter 5 focuses on quantifying nutrient and pesticide concentrations in the surface waters at the Reserve’s System-Wide Monitoring Program (SWMP) sites. Chapter 6 is a brief summary discussion that highlights key findings of the entire suite of studies.

Integration of fisheries acoustics surveys and bathymetric mapping to characterize midwater-seafloor habitats of US Virgin Islands and Puerto Rico (2008-2010)

NOAA’s Coral Reef Conservation program (CRCP) develops coral reef management priorities by bringing together various partners to better understand threats to coral reef ecosystems with the goal of conserving, protecting and restoring these resources. Place-based and ecosystem-based management approaches employed by CRCP require that spatially explicit information about benthic habitats and fish utilization are available to characterize coral reef ecosystems and set conservation priorities. To accomplish this, seafloor habitat mapping of coral reefs around the U.S. Virgin Islands (USVI) and Puerto Rico has been ongoing since 2004. In 2008, fishery acoustics surveys were added to NOAA survey missions in the USVI and Puerto Rico to assess fish distribution and abundance in relation to benthic habitats in high priority conservation areas. NOAA’s National Centers for Coastal Ocean Science (NCCOS) have developed fisheries acoustics survey capabilities onboard the NOAA ship Nancy Foster to complement the CRCP seafloor habitat mapping effort spearheaded by the Center for Coastal Monitoring and Assessment Biogeography Branch (CCMA-BB). The integration of these activities has evolved on the Nancy Foster over the three years summarized in this report. A strategy for improved operations and products has emerged over that time. Not only has the concurrent operation of multibeam and fisheries acoustics surveys been beneficial in terms of optimizing ship time and resources, this joint effort has advanced an integrated approach to characterizing bottom and mid-water habitats and the fishes associated with them. CCMA conducts multibeam surveys to systematically map and characterize coral reef ecosystems, resulting in products such as high resolution bathymetric maps, backscatter information, and benthic habitat classification maps. These products focus on benthic features and live bottom habitats associated with them. NCCOS Centers (the Center for Coastal Fisheries and Habitat Research and the Center for Coastal Environmental Health and Biomolecular Research) characterize coral reef ecosystems by using fisheries acoustics methods to capture biological information through the entire water column. Spatially-explicit information on marine resources derived from fisheries acoustics surveys, such as maps of fish density, supports marine spatial planning strategies and decision making by providing a biological metric for evaluating coral reef ecosystems and assessing impacts from pollution, fishing pressure, and climate change. Data from fisheries acoustics surveys address management needs by providing a measure of biomass in management areas, detecting spatial and temporal responses in distribution relative to natural and anthropogenic impacts, and identifying hotspots that support high fish abundance or fish aggregations. Fisheries acoustics surveys conducted alongside multibeam mapping efforts inherently couple water column data with information on benthic habitats and provide information on the heterogeneity of both benthic habitats and biota in the water column. Building on this information serves to inform resource managers regarding how fishes are organized around habitat structure and the scale at which these relationships are important. Where resource managers require place-based assessments regarding the location of critical habitats along with high abundances of fish, concurrent multibeam and fisheries acoustics surveys serve as an important tool for characterizing and prioritizing coral reef ecosystems. This report summarizes the evolution of fisheries acoustics surveys onboard the NOAA ship Nancy Foster from 2008 to 2010, in conjunction with multibeam data collection, aimed at characterizing benthic and mid-water habitats in high priority conservation areas around the USVI and Puerto Rico. It also serves as a resource for the continued development of consistent data products derived from acoustic surveys. By focusing on the activities of 2010, this report highlights the progress made to date and illustrates the potential application of fisheries data derived from acoustic surveys to the management of coral reef ecosystems.