Scientific assessment of hypoxia in U.S. coastal waters

The occurrence of hypoxia, or low dissolved oxygen, is increasing in coastal waters worldwide and represents a significant threat to the health and economy of our Nation’s coasts and Great Lakes. This trend is exemplified most dramatically off the coast of Louisiana and Texas, where the second largest eutrophication-related hypoxic zone in the world is associated with the nutrient pollutant load discharged by the Mississippi and Atchafalaya Rivers. Aquatic organisms require adequate dissolved oxygen to survive. The term “dead zone” is often used in reference to the absence of life (other than bacteria) from habitats that are devoid of oxygen. The inability to escape low oxygen areas makes immobile species, such as oysters and mussels, particularly vulnerable to hypoxia. These organisms can become stressed and may die due to hypoxia, resulting in significant impacts on marine food webs and the economy. Mobile organisms can flee the affected area when dissolved oxygen becomes too low. Nevertheless, fish kills can result from hypoxia, especially when the concentration of dissolved oxygen drops rapidly. New research is clarifying when hypoxia will cause fish kills as opposed to triggering avoidance behavior by fish. Further, new studies are better illustrating how habitat loss associated with hypoxia avoidance can impose ecological and economic costs, such as reduced growth in commercially harvested species and loss of biodiversity, habitat, and biomass. Transient or “diel-cycling” hypoxia, where conditions cycle from supersaturation of oxygen late in the afternoon to hypoxia or anoxia near dawn, most often occurs in shallow, eutrophic systems (e.g., nursery ground habitats) and may have pervasive impacts on living resources because of both its location and frequency of occurrence.

Evaluation of the economic costs and benefits of methods for reducing nutrient loads to the Gulf of Mexico: Topic 6 Report for the Integrated Assessment on Hypoxia in the Gulf of Mexico.

In this report we analyze the Topic 5 report’s recommendations for reducing nitrogen losses to the Gulf of Mexico (Mitsch et al. 1999). We indicate the relative costs and cost-effectiveness of different control measures, and potential benefits within the Mississippi River Basin. For major nonpoint sources, such as agriculture, we examine both national and basin costs and benefits. Based on the Topic 2 economic analysis (Diaz and Solow 1999), the direct measurable dollar benefits to Gulf fisheries of reducing nitrogen loads from the Mississippi River Basin are very limited at best. Although restoring the ecological communities in the Gulf may be significant over the long term, we do not currently have information available to estimate the benefits of such measures to restore the Gulf’s long-term health. For these reasons, we assume that measures to reduce nitrogen losses to the Gulf will ultimately prove beneficial, and we concentrate on analyzing the cost-effectiveness of alternative reduction strategies. We recognize that important public decisions are seldom made on the basis of strict benefit–cost analysis, especially when complete benefits cannot be estimated. We look at different approaches and different levels of these approaches to identify those that are cost-effective and those that have limited undesirable secondary effects, such as reduced exports, which may result in lost market share. We concentrate on the measures highlighted in the Topic 5 report, and also are guided by the source identification information in the Topic 3 report (Goolsby et al. 1999). Nonpoint sources that are responsible for the bulk of the nitrogen receive most of our attention. We consider restrictions on nitrogen fertilizer levels, and restoration of wetlands and riparian buffers for denitrification. We also examine giving more emphasis to nitrogen control in regions contributing a greater share of the nitrogen load.

Ecological change in Lough Erne: influence of catchment changes and species invasions

Lough Erne in Northern Ireland has been the subject of much research over the last 30 years by, amongst others, the Department of Agriculture and Rural Development (DARD). In this article, the authors provide a summary of a workshop held on the 16–17th October 2003 in Enniskillen, on the shores of Lough Erne, which gave an opportunity to step back and take a holistic look at the Erne lakes. Ecological change has been driven by many factors, including land use changes and species invasions. The workshop consisted of five sessions which are summarised in this article: Session 1 – Invasive species, nutrients, phytoplankton and macrophytes; Session 2 – Zooplankton, benthic macroinvertebrates and fish; Session 3 – An ecosystem approach – relating the previous sessions; Session 4 – How does Lough Erne fit into lake classifications? Implications of the Water Framework Directive; Session 5 – Using new techniques to examine food webs and species invasions. Identifying a future research programme for Lough Erne.

Applying systems ecology to the analysis of integrated agriculture-aquaculture farms

The article suggests a preliminary list of properties as a point of departure for quantifying various ecological facets of the integrated agriculture-aquaculture farms.

Perspectives from agriculture: advances in livestock breeding - implications for aquaculture genetics

In this paper we present livestock breeding developments that could be taken into consideration in the genetic improvement of farmed aquaculture species, especially in freshwater fish. Firstly, the current breeding objective in aquatic species has focused almost exclusively on the improvement of body weight at harvest or on growth related traits. This is unlikely to be sufficient to meet the future needs of the aquaculture industry. To meet future demands breeding programs will most likely have to include additional traits, such as fitness related ones (survival, disease resistance), feed efficiency, or flesh quality, rather than only growth performance. In order to select for a multi-trait breeding objective, genetic variation in traits of interest and the genetic relationships among them need to be estimated. In addition, economic values for these traits will be required. Generally, there is a paucity of data on variable and fixed production costs in aquaculture, and this could be a major constraint in the further expansion of the breeding objectives. Secondly, genetic evaluation systems using the restricted maximum likelihood method (REML) and best linear unbiased prediction (BLUP) in a framework of mixed model methodology could be widely adopted to replace the more commonly used method of mass selection based on phenotypic performance. The BLUP method increases the accuracy of selection and also allows the management of inbreeding and estimation of genetic trends. BLUP is an improvement over the classic selection index approach, which was used in the success story of the genetically improved farmed tilapia (GIFT) in the Philippines, with genetic gains from 10 to 20 per cent per generation of selection. In parallel with BLUP, optimal genetic contribution theory can be applied to maximize genetic gain while constraining inbreeding in the long run in selection programs. Thirdly, by using advanced statistical methods, genetic selection can be carried out not only at the nucleus level but also in lower tiers of the pyramid breeding structure. Large scale across population genetic evaluation through genetic connectedness using cryopreserved sperm enables the comparison and ranking of genetic merit of all animals across populations, countries or years, and thus the genetically superior brood stock can be identified and widely used and exchanged to increase the rate of genetic progress in the population as a whole. It is concluded that sound genetic programs need to be established for aquaculture species. In addition to being very effective, fully pedigreed breeding programs would also enable the exploration of possibilities of integrating molecular markers (e.g., genetic tagging using DNA fingerprinting, marker (gene) assisted selection) and reproductive technologies such as in-vitro fertilization using cryopreserved spermatozoa.

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.

An ecological characterization of the marine resources of Vieques, Puerto Rico. Part I: Historical data synthesis

From the 1940s until 2003, portions of the island of Vieques, a municipality within the Commonwealth of Puerto Rico, were used by the US Navy as a base and training facility, resulting in development and zoning history that differ in comparison to other Caribbean islands. The majority of former Navy lands are now under the jurisdiction of the Department of the Interior’s Fish and Wildlife Service as a National Wildlife Refuge, while a smaller percentage of land was transferred to the Vieques municipality and the Puerto Rico Conservation Trust. An analysis of the distribution and status of the marine resources is timely in light of the recent land transfer, increases in development and tourism, and potential changes in marine zoning around the island. To meet this need, NOAA’s Biogeography Branch, in cooperation with the Office of Response and Restoration and other local and regional partners, conducted Part I of an ecological characterization to integrate historical data and research into a synthesis report. The overall objective of this report is to provide resource managers and residents a comprehensive characterization of the marine resources of Vieques to support research, monitoring, and management. For example, knowledge of the spatial distribution of physical features, habitats, and biological communities is necessary to make an informed decision of the establishment and placement of a marine protected area (MPA). The report is divided into chapters based on the physical environment (e.g., climate, geology, bathymetry), habitat types (e.g., reefs and hardbottom, seagrasses, mangroves) and major faunal groups (e.g. fish, turtles, birds). Each section includes five subsections: an overview, description of the relevant literature, methods of analysis, information on the distribution, status and trends of the particular resource, and a discussion of ecological linkages with other components of the Vieques marine ecosystem and surrounding environment. The physical environment of Vieques is similar to other islands within the Greater Antilles chain, with some distinctions. The warm, tropical climate of Vieques, mediated by the northeasterly trade winds, is characterized by a dry season (December-April) and a rainy season (May-November), the latter of which is characterized by the occasional passage of tropical cyclones. Compared to mainland Puerto Rico, Vieques is characterized by lower elevation, less annual precipitation, and higher average temperatures. The amount of annual precipitation also varies spatially within Vieques, with the western portion of the island receiving higher amounts of rainfall than further east. While the North Equatorial Current dominates the circulation pattern in the Greater Antilles region, small scale current patterns specific to Vieques are not as well characterized. These physical processes are important factors mitigating the distribution and composition of marine benthic habitats around Vieques. In general, the topography of Vieques is characterized by rolling hills. Mt. Pirata, the tallest point at 301 m, is located near the southwest coast. In the absence of island wide sedimentation measurements, information on land cover, slope, precipitation, and soil type were used to estimate relative erosion potential and sediment delivery for each watershed. While slope and precipitation amount are the primary driving factors controlling runoff, land use practices such as urban development, military activity, road construction, and agriculture can increase the delivery of pollution and sediments to coastal waters. Due to the recent land transfer, increased development and tourism is expected, which may result in changes in the input of sediments to the coastal environment.

Proposal to permit experimental artificial reefs inside and outside the Big Sycamore Canyon Ecological Reserve

(Document pdf contains 19 pages)

Annotated bibliography on socio-economic and ecological impacts of marine protected areas in Pacific Island countries

The bibliography is to highlight impacts on fisheries and livelihoods attributed to coral reef marine protected areas in Pacific Island countries and territories. Included in this collection is literature that reports various forms of reef area management practiced in Pacific Island countries: reserves, sanctuaries, permanent or temporary closed areas, community and traditional managed areas. (Document contains 36 pages)

Catch-22: conservation, communities and the privatization of B.C. fisheries. An economic, social and ecological impact study

pdf contains 47 pages

Food habits as an ecological partitioning mechanism in the nearshore rockfishes (Sebastes) of Carmel Bay, California

In the kelp forests of Carmel Bay there are six common rockfishes (Sebastes). Three are pelagic (S. serranoides, S. mystinus, and S. melanops) and two are demersal (S. chrysomelas and S. carnatus). The sixth (S. atrovirens) is generally found a few meters above the sea floor. The pelagic rockfishes which are spatially overlapping have different feeding habits. All rockfishes except S. mystinus utilize juvenile rockfishes as their primary food source during the upwelling season. Throughout the non-upwelling season, most species consume invertebrate prey. The pelagic rockfishes have shorter maxillary bones and longer gill rakers than their demersal congeners, both specializations for taking smaller prey. They also have longer intestines, enabling them to utilize less digestable foods. S. mystinus, which has the longest intestine, may be able to use algae as a food source. Fat reserves are accumulated from July through October, when prey is most abundant. Fat is depleted throughout the rest of the year as food becomes scarce and development of sexual organs takes place. Gonad development occurs from November through February for all species except S. atrovirens.

Prediction, Chaos and Ecological Perspective.

As defined, the modeling procedure is quite broad. For example, the chosen compartments may contain a single organism, a population of organisms, or an ensemble of populations. A population compartment, in turn, could be homogeneous or possess structure in size or age. Likewise, the mathematical statements may be deterministic or probabilistic in nature, linear or nonlinear, autonomous or able to possess memory. Examples of all types appear in the literature. In practice, however, ecosystem modelers have focused upon particular types of model constructions. Most analyses seem to treat compartments which are nonsegregated (populations or trophic levels) and homogeneous. The accompanying mathematics is, for the most part, deterministic and autonomous. Despite the enormous effort which has gone into such ecosystem modeling, there remains a paucity of models which meets the rigorous &! validation criteria which might be applied to a model of a mechanical system. Most ecosystem models are short on prediction ability. Even some classical examples, such as the Lotka-Volterra predator-prey scheme, have not spawned validated examples.