Effects of reducing nutrient loads to surface waters within the Mississippi River Basin and the Gulf of Mexico: Topic 4 Report for the Integrated Assessment on Hypoxia in the Gulf of Mexico

The overall goal of this assessment was to evaluate the effects of nutrient-source reductions that may be implemented in the Mississippi River Basin (MRB) to reduce the problem of low oxygen conditions (hypoxia) in the nearshore Gulf of Mexico. Such source reductions would affect the quality of surface waters—streams, rivers, and reservoirs—in the drainage basin itself, as well as nearshore Gulf waters. The task group’s work was divided into addressing the effects of nutrient-source reductions on: (1) surface waters in the MRB and (2) hypoxia in the Gulf of Mexico.

Flux and sources of nutrients in the Mississippi-Atchafalaya River Basin: Topic 3 Report for the Integrated Assessment on Hypoxia in the Gulf of Mexico.

Ths report addresses the following two questions: 1) What are the loads (flux) of nutrients transported from the Mississippi-Atchafalaya River Basin to the Gulf of Mexico, and where do they come from within the basin? 2) What is the relative importance of specific human activities, such as agriculture, point-source discharges, and atmospheric deposition in contributing to these loads? These questions were addressed by first estimating the flux of nutrients from the Mississippi-Atchafalaya River Basin and about 50 interior basins in the Mississippi River system using measured historical streamflow and water quality data. Annual nutrient inputs and outputs to each basin were estimated using data from the National Agricultural Statistics Service, National Atmospheric Deposition Program, and point-source data provided by the USEPA. Next, a nitrogen mass balance was developed using agricultural statistics, estimates of nutrient cycling in agricultural systems, and a geographic information system. Finally, multiple regression models were developed to estimate the relative contributions of the major input sources to the flux of nitrogen and phosphorus to the Gulf of Mexico.

Ecological and economic consequences of hypoxia: Topic 2 Report for the Integrated Assessment on Hypoxia in the Gulf of Mexico

In this report we have attempted to evaluate the ecological and economic consequences of hypoxia in the northern Gulf of Mexico. Although our initial approach was to rely on published accounts, we quickly realized that the body of published literature deahng with hypoxia was limited, and we would have to conduct our own exploratory analysis of existing Gulf data, or rely on published accounts from other systems to infer possible or potential effects of hypoxia. For the economic analysis, we developed a conceptual model of how hypoxia-related impacts could affect fisheries. Our model included both supply and demand components. The supply model had two components: (1) a physical production function for fish or shrimp, and (2) the cost of fishing. If hypoxia causes the cost of a unit of fishing effort to change, then this will result in a shift in supply. The demand model considered how hypoxia might affect the quality of landed fish or shrimp. In particular, the market value per pound is lower for small shrimp than for large shrimp. Given the limitations of the ecological assessment, the shallow continental shelf area affected by hypoxia does show signs of hypoxia-related stress. While current ecological conditions are a response to a variety of stressors, the effects of hypoxia are most obvious in the benthos that experience mortality, elimination of larger long-lived species, and a shifting of productivity to nonhypoxic periods (energy pulsing). What is not known is whether hypoxia leads to higher productivity during productive periods, or simply to a reduction of productivity during oxygen-stressed periods. The economic assessment based on fisheries data, however, failed to detect effects attributable to hypoxia. Overall, fisheries landings statistics for at least the last few decades have been relatively constant. The failure to identify clear hypoxic effects in the fisheries statistics does not necessarily mean that they are absent. There are several possibilities: (1) hypoxic effects are small relative to the overall variability in the data sets evaluated; (2) the data and the power of the analyses are not adequate; and (3) currently there are no hypoxic effects on fisheries. Lack of identified hypoxic effects in available fisheries data does not imply that effects would not occur should conditions worsen. Experience with other hypoxic zones around the globe shows that both ecological and fisheries effects become progressively more severe as hypoxia increases. Several large systems around the globe have suffered serious ecological and economic consequences from seasonal summertime hypoxia; most notable are the Kattegat and Black Sea. The consequences range from localized loss of catch and recruitment failure to complete system-wide loss of fishery species. If experiences in other systems are applicable to the Gulf of Mexico, then in the face of worsening hypoxic conditions, at some point fisheries and other species will decline, perhaps precipitously.

Characterization of Hypoxia: Topic I Report for the Integrated Assessment on Hypoxia in the Gulf of Mexico

Nutrient overenrichment from human activities is one of the major stresses affecting coastal ecosystems. There is increasing concern in many areas around the world that an oversupply of nutrients from multiple sources is having pervasive ecological effects on shallow coastal and estuarine areas. These effects include reduced light penetration, loss of aquatic habitat, harmfid algal blooms, a decrease in dissolved oxygen (or hypoxia), and impacts on living resources. The largest zone of oxygen-depleted coastal waters in the United States, and the entire western Atlantic Ocean, is found in the northern Gulf of Mexico on the Louisiana-Texas continental shelf. This zone is influenced by the freshwater discharge and nutrient flux of the Mississippi River system. This report describes the seasonal, interannual, and long-term variability in hypoxia in the northern Gulf of Mexico and its relationship to nutrient loading. It also documents the relative roles of natural and human-induced factors in determining the size and duration of the hypoxic zone.

Integrated conceptual ecosystem model development for the Florida Keys/Dry Tortugas coastal marine ecosystem: MARine Estuarine goal Setting (MARES) for South Florida

The overall goal of the MARine and Estuarine goal Setting (MARES) project for South Florida is “to reach a science-based consensus about the defining characteristics and fundamental regulating processes of a South Florida coastal marine ecosystem that is both sustainable and capable of providing the diverse ecosystem services upon which our society depends.” Through participation in a systematic process of reaching such a consensus, science can contribute more directly and effectively to the critical decisions being made by both policy makers and by natural resource and environmental management agencies. The document that follows briefly describes the MARES project and this systematic process. It then describes in considerable detail the resulting output from the first two steps in the process, the development of conceptual diagrams and an Integrated Conceptual Ecosystem Model (ICEM) for the first subregion to be addressed by MARES, the Florida Keys/Dry Tortugas (FK/DT). What follows with regard to the FK/DT is the input received from more than 60 scientists, agency resource managers, and representatives of environmental organizations beginning with a workshop held December 9-10, 2009 at Florida International University in Miami, Florida.

Integrated conceptual ecosystem model development for the southeast Florida coastal marine ecosystem: MARine Estuarine goal Setting (MARES) for South Florida

The overall goal of the MARES (MARine and Estuarine goal Setting) project for South Florida is “to reach a science-based consensus about the defining characteristics and fundamental regulating processes of a South Florida coastal marine ecosystem that is both sustainable and capable of providing the diverse ecosystem services upon which our society depends.” Through participation in a systematic process of reaching such a consensus, science can contribute more directly and effectively to the critical decisions being made both by policy makers and by natural resource and environmental management agencies. The document that follows briefly describes MARES overall and this systematic process. It then describes in considerable detail the resulting output from the first step in the process, the development of an Integrated Conceptual Ecosystem Model (ICEM) for the third subregion to be addressed by MARES, the Southeast Florida Coast (SEFC). What follows with regard to the SEFC relies upon the input received from more than 60 scientists, agency resource managers, and representatives of environmental organizations during workshops held throughout 2009–2012 in South Florida.

Integrated conceptual ecosystem model development for the southwest Florida shelf coastal marine ecosystem: MARine Estuarine goal Setting (MARES) for South Florida

The overall goal of the MARine and Estuarine goal Setting (MARES) project for South Florida is “to reach a science-based consensus about the defining characteristics and fundamental regulating processes of a South Florida coastal marine ecosystem that is both sustainable and capable of providing the diverse ecosystem services upon which our society depends.” Through participation in a systematic process of reaching such a consensus, science can contribute more directly and effectively to the critical decisions being made by both policy makers and by natural resource and environmental management agencies. The document that follows briefly describes the MARES project and this systematic process. It then describes in considerable detail the resulting output from the first two steps in the process, the development of conceptual diagrams and an Integrated Conceptual Ecosystem Model (ICEM) for the second subregion to be addressed by MARES, the Southwest Florida Shelf (SWFS). What follows with regard to the SWFS is the input received from more than 60 scientists, agency resource managers, and representatives of environmental organizations beginning with a workshop held August 19-20, 2010 at Florida Gulf Coast University in Fort Myers, Florida.

Support for integrated ecosystem assessments of NOAA’s National Estuarine Research Reserve System (NERRS): assessment of ecological condition and stressor impacts in subtidal waters of the Sapelo Island National Estuarine Research Reserve

A study was conducted in June 2009 to assess the current status of ecological condition and potential human-health risks throughout subtidal estuarine waters of the Sapelo Island National Estuarine Research Reserve (SINERR) along the coast of Georgia. Samples were collected for multiple indicators of ecosystem condition, including water quality (dissolved oxygen, salinity, temperature, pH, nutrients and chlorophyll, suspended solids, fecal coliform bacteria and coliphages), sediment quality (granulometry, organic matter content, chemical contaminant concentrations), biological condition (diversity and abundance of benthic fauna, fish tissue contaminant levels and pathologies), and human dimensions (fish-tissue contaminant levels relative to human-health consumption limits, various aesthetic properties). Use of a probabilistic sampling design facilitated the calculation of statistics to estimate the spatial extent of the Reserve classified according to various categories (i.e., Good, Fair, Poor) of ecological condition relative to established thresholds of these indicators, where available. Overall, the majority of subtidal habitat in the SINERR appeared to be healthy, with over half (56.7 %) of the Reserve area having water quality, sediment quality, and benthic biological condition indicators rated in the healthy to intermediate range of corresponding guideline thresholds. None of the stations sampled had one or more indicators in all three categories rated as poor/degraded. While these results are encouraging, it should be noted that one or more indicators were rated as poor/degraded in at least one of the three categories over 40% of the Reserve study area, represented by 12 of the 30 stations sampled. Although measures of fish tissue chemical contamination were not included in any of the above estimates, a number of trace metals, pesticides, polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) were found at low yet detectable levels in some fish at stations where fish were caught. Levels of mercury and total PCBs in some fish specimens fell within EPA guideline values considered safe, given a consumption rate of no more than four fish meals per month. Moreover, PCB congener profiles in sediments and fish in the SINERR exhibit a relative abundance of higher-chlorinated homologs which are uniquely characteristic of Aroclor 1268. It has been well-documented that sediments and fish in the creeks and marshes near the LCP Chemicals Superfund site, near Brunswick, Georgia, also display this congener pattern associated with Aroclor 1268, a highly chlorinated mixture of PCBs used extensively at a chlor-alkali plant that was in operation at the LCP site from 1955-1994. This report provides results suggesting that the protected habitats lying within the boundaries of the SINERR may be experiencing the effects of a legacy of chemical contamination at a site over 40km away. These effects, as well as other potential stressors associated with increased development of nearby coastal areas, underscore the importance of establishing baseline ecological conditions that can be used to track potential changes in the future and to guide management and stewardship of the otherwise relatively unspoiled ecosystems of the SINERR.

An integrated biogeographic assessment of reef fish populations and fisheries in Dry Tortugas: Effects of No-take Reserves

The Tortugas Integrated Biogeographic Assessment presents a unique analysis of demographic changes in living resource populations, as well as societal and socioeconomic benefits that resulted from the Tortugas Ecological Reserves during the first five years after their implementation. In 2001, state and federal agencies established two no-take reserves within the region as part of the Florida Keys National Marine Sanctuary. The northern reserve (Tortugas Ecological Reserve North) was established adjacent to the Dry Tortugas National Park, which was first declared a national monument in 1935. The reserves were designed to protect a healthy coral reef ecosystem that supports diverse faunal assemblages and fisheries, serves as important spawning grounds for groupers and snappers, and includes essential feeding and breeding habitats for seabirds. The unique ecological qualities of the Tortugas region were recognized as far back as 1850, and it remains an important ecosystem and research area today. The two main goals of the Tortugas Ecological Reserve Integrated Ecological Assessment were: 1) to determine if demographic changes such as increases in abundance, average size and spawning potential of exploited populations occurred in the Tortugas region after reserve implementation; and 2) whether short-term economic losses occurred to fishers displaced by the reserve. This project utilized a biogeographic approach in which information on the physical features (i.e., habitat) and oceanographic patterns were first used to determine the spatial distribution of selected fish populations within and outside the Tortugas Ecological Reserve. Before-and-after reserve implementation comparisons of selected fish populations were then conducted to determine if demographic changes occurred in reef fish assemblages. These comparisons were done for the Tortugas region and also for a subset of available habitats within the Tortugas Ecological Reserve Study Area. Social and economic impacts of the reserves were determined through: 1) analyses of commercial landings and revenues from fishers, operating in the Tortugas region before and after reserve implementation and 2) surveys of recreational tour guides. Analyses of the commercial landings and revenues excluded areas inside Dry Tortugas National Park because commercial fishing has been prohibited within park boundaries since 1992. Key findings and outcomes of this integrated ecological assessment are organized by chapter and listed below.

Work plan for analytical support of an integrated ecosystem assessment of the California Current Large Marine Ecosystem, FY11 ‐ FY13

NOAA/NCCOS is conducting the following work for the NOAA California Current Integrated Ecosystem Assessment, in support of the NOAA/NMFS Northwest Fisheries Science Center.

Farmer-scientist research partnerships for integrated agriculture-aquaculture

A realistic alternative to traditional technology development and transfer has been utilized by the International Center for Living Aquatic Resources Management (ICLARM) to integrate pond fish culture into low-input farming systems in Malawi. Resource mapping was used to assess farm resources and constraints and introduce the concept of integrated resource management (IRM), the synergistic movement of resources between and among farm and household enterprises. Farmer-led IRM research projects are conducted on-farm and monitored by researchers through direct observation and on-station simulation of constraints and management practices. Technology-adoption rates by farmers involved in a pilot activity was 65% compared to 0% by farmers exposed only to top-down extension approaches. Within two years of adoption, every participating farmer had transferred the technology to an average of four other farmers without the involvement of the extension services.

Integrated aquaculture-agriculture adoption and impact in rainfed farming systems in Sakata, Malawi

ICLARM introduced integrated aquaculture-agriculture (IAA) in Sakata, Malawi three years ago. Since that time, and without extension support, the number of farmers with ponds increased from 4 in 1993/94 to 12 in 1995/96. To learn why and how IAA is spreading, a study of impact and adoption was conducted in the 1995/96 production season. Interviews were conducted with farmers to discuss lAA and collect data on farm function through the use of bioresource flow diagrams. Motivations given by farmers as to why they adopted IAA were to improve household nutrition and income. Constraints to adoption identified by farmers were availability of labor and capital to purchase inputs

Study on primary production and its importance in an integrated fisheries research programme

The importance of the ocean as a source of cheap protein food is too well-known to be emphasised. In recent years there has been a tremendous increase in the fishing activity in all maritime nations and during the last few years the total world production has markedly grown. This study explains the importance of a planned exploitation according to scientific principles to preserve the availability and natural fluctuations in the abundance of stocks of marine fish and other commercially important organisms.

A rapid procedure for the approximation of bacterial load in fishery products

The production of colour by homogenised fish material in a simplified sugar medium containing and acid indicator has been made use of for the rapid approximation of bacterial load in such products. The medium thus developed contains poptone, tryptone, yeast extract, sodium chloride and beef extract besides dextrose. The time of colour production is influenced to some extent by the level of sodium chloride in the medium and is almost always inversely proportional to the bacterial load in the homogenate.