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This paper presents a coastal migration index (CMI) useful for decision-making in the current scenario of sea-level rise (SLR) due to climate change. The CMI includes coastal human population density, degree of urbanization, and coastal-flooding penetration. Quantitative and qualitative statistical techniques and the geographic information system ArcGIS View 9.0 were used. Further, a panel of fifteen international experts in coastal management issues was consulted to establish and validate the CMI. Results led to three index components based on 22 indicators. CMI was applied in the state of Tamaulipas, Mexico and in Santiago de Cuba province, Cuba. According to CMI estimates, the risk levels associated with SLR for human settlements analyzed in Mexico and Cuba were 5.3% and 11.0%, respectively. The most severely affected communities will require resettlement. Meanwhile, the CMI determined that 15.8% of the Mexican territory studied will be able to withstand the effects of SLR through the management of engineering works that will protect human settlements. The CMI determined that 79.0%, in the case of Tamaulipas, as well as 89.0% of the Cuban territory, will not require new policies or guidelines to promote conservation and protection of coastal natural resources. Lastly, the method used allowed for creation of a CMI stoplight map useful to coastal decision-makers to adopt sound management actions.

Human activities often drive landscape degradation and the associated loss of value. This paper describes a method that, by integrating multiple factors, characterize landscape value to establish relevant and effective management practices. The new integrated method for landscape assessment (IMLA) is a four-step model that includes: (i) establishment of a general theoretical basis for sustainability relevant metrics, (ii) characterization of the landscape, (iii) landscape valuation, (iv) recommendations for landscape value management. Each step includes different interactive components of analysis. The new IMLA considers the potential range of values associated with each landscape unit and facilitates sustainable landscape management. The method is systematic and includes both inductive and deductive reasoning. Its articulation is represented in the conjunction and overlapping of all factors and variables considered. IMLA was tested in Santiago de Cuba Bay (Cuba) and used to determine five landscape scopes, eight first-order landscape units and 29 s-order units. It proved to be a useful tool to establish landscape values and sound management strategies. Application of IMLA in Cuba will help local authorities institute land-use plans and to establish decision-making processes that include valuation of cultural landscapes.

Este artículo contiene 10 páginas, 3 figuras, 2 tablas., Defining impact significance is the main technical task that influences decision-making during the Environmental Licensing Procedure (ELP). The ELP begins with screening to determine potentially significant impacts of the proposed project. Scoping then follows to address any interventions deemed worthy of attention in the production of an Environmental Impact Assessment (EIA). This will include consideration of relevant landforms and geomorphological processes. However, preliminary assessments of environmental impacts often lack the scientific robustness to procure substantive and transactive effectiveness. This review presents an examination of the established practices of screening and scoping while highlighting the foremost challenges to improve the technical grounds of the ELP. The analysis of screening and scoping practices stresses the need for novel methods that ensure the sequential reasoning between their criteria while improving the preliminary evaluation of impact significance. Reducing the inherent subjectivity of discretionary judgment requires scientific methodologies that acknowledge the interaction between the natural system and human interventions, which has been addressed by geomorphological research. The knowledge consolidated in this review opens the gate to explore the compatibility between the United Nations strategy of Ecosystem Approach (EA) with the ELP through a novel geomorphological interpretation of the EIA. Therefore, this diagnosis demonstrate that screening and scoping practices would benefit from reliable methods that balance the precautionary principle with the efficient character required in the ELP., This contribution is a product of the post-doctoral research No 80740-103-2020, financed by the National Financing Fund ‘‘FRANCISCO JOSÉ DE CALDAS” and the Ministry of Science, Technology and Innovation of Colombia. The authors would like to thank PROPLAYAS Network, of which they are members, and to the Project INDEX No. INV.1106-01-002-15 ‘‘Cultural practices and environmental certification of beaches: a contribution for the sustainable development in the insular states” of Universidad de la Costa of Barranquilla, Colombia.

The new blue economy (NBE) will require a workforce educated in new ways. The old blue economy (OBE) is built of a legacy of labor relationships shaped by centuries of profit-motivated exploitation of workers and aquatic resources. This toll of exploitation falls hardest on people of color. Education of the workforce of the NBE must reject the tradition of exploitation for a new vision of shared ownership that places high value on human diversity and sustainable use of marine resources. This means educating all participants in the workforce, from laborers to managers, about alternative business models and the value of diversity and equity.

This book is about the intersection between the food system, the condition of the Chesapeake Bay ecosystem, and the health of the people that live there. It takes a historical approach examining how the food system developed from early colonial times to the present. The book introduces the reader to the basic science governing the estuary and human health. It then examines the issues of exploitation of key animal populations, effects of industrial/chemical agriculture on the ecosystem, diet driven human health outcomes, pollution from the food system, economics and ethics of the food system, current policy environment, and the nexus between the food system and climate change in the Chesapeake Bay Region. The Standard American Diet (SAD) is examined from the perspectives of the impacts on the health of the ecosystem that produces it and the people that consume it. The authors introduce the concept that the food system drives eutrophication of people as well as ecosystems. The book presents evidence for the efficacy of replacing the SAD with a food system restructured to produce a whole foods plant based diet. It is written with social context that addresses issues of gender and race as they pertain to the food system and health outcomes. It also notes particular contribution made by women and people of color.

Climate change is reshaping the Chesapeake Bay ecosystem and its linked food system. Sea level rise and increased precipitation drive regular flooding events and the erosion of islands and coastal features. This results in the loss of habitat for various species of birds and fishes. Increased temperatures extend the growing season and reduce the incidence of frosts. Rising water temperatures accommodate the immigration of warm-adapted species and endanger populations of cold ones. Increased temperature interacts with cultural eutrophication to extend the duration and extent of seasonal hypoxia. Higher regional temperatures threaten human health, particularly populations of poorer residents that lack refuge from heatwaves and flooding events. Acidification of the Bay, which is linked to climate change agents, endangers species that rely upon calcium carbonate for shell and skeleton. Emission of greenhouse gases (GHGs, primarily CO2, NO2, CH4) from human economic activity drives climate change. The food system accounts for 25–30% of human GHGs emissions. Half of these comes from livestock, which contribute 14.5% of the global anthropogenic GHG load. Eliminating animal-based foods, particularly ruminants (cattle) would facilitate building a sustainable food system with improved health outcomes for the residents of the Chesapeake Bay Region.

Plastic pollution is a widespread problem across the world’s oceans, bays, estuaries and rivers. Much of this waste is the residue of food system packaging. Excessive production of these durable polymers and inappropriate disposal lead to their accumulation in aquatic environments. Large pieces of plastic debris are a regular feature of shorelines in the Chesapeake Bay, as is true around the world. Over time such plastic debris may be partially degraded, primarily by UV light and abrasion, and fragmented. In fact, a majority of plastic debris falls into the category of microplastics, i.e. debris smaller than 5 mm. The abundance of microplastics in the tributaries of the Chesapeake Bay has been linked to the population density of the surrounding area. Importantly, both large plastic debris items and microplastics threaten marine organisms through ingestion or entanglement. Another threat may accompany the plastic; the surface of the debris may carry sorbed chemical contaminants or pathogens that harm aquatic life. Some plastic polymers also contain chemical additives. These additives may be toxic to aquatic organisms and concentrate at higher trophic levels of the food chain. These phenomena are still being explored by researchers. At present, there is inadequate research detailing the distribution of plastics in the Chesapeake Bay. We explore here the plastic pollution issue, how it may impact the health of the Chesapeake Bay, and possible solutions, with particular attention to food system packaging.

The introduction of domesticated animals into the Chesapeake Bay regions’ food system had profound consequences for the health of the ecosystem and its people. Draft animals provided the labor to clear and cultivate the majority of the Chesapeake Bay Watershed by 1900. Pigs brought by English colonists became important sources of food for both the settlers and native peoples. Initially, introduced chickens played a persistent but minor role in the food system. This changed with the development of the chicken for meat (broiler) industry on the Bay’s Delmarva Peninsula in the 1920s. The broiler industry pioneered the use of concentrated animal feeding operations (CAFOs) and vertical integration of all aspects of production, a model now dominating the entire livestock enterprise. This propelled a 50% rise in per capita consumption of animal-based foods and attendant rise in human diseases, particularly coronary artery disease. Industrialization of chicken also increased its share of the animal products market sevenfold. The broiler industry pioneered the use of antibiotics as growth promoters, resulting in development of antibiotic-resistant pathogens. Poultry workers face various health problems, including increased rates of respiratory disease and certain cancers. The poultry industry is the major source of Salmonella poisoning. Broiler chickens suffer crowded and polluted conditions in CAFOs. These CAFOs dominate the landscape of the Delmarva, producing air and water pollution. Nitrogen as a waste product from the industry reaches the Bay and is a major source of eutrophication.

The end of World War II brought DDT and other organic pesticides to Chesapeake Bay agriculture. These new insecticides and herbicides supported the industrialization of farming that primarily produced feedstock for the manufacture of animal-based foods. The widespread use of these new chemicals constituted a war on nature with the intent of poisoning non-human animals that ate crops and weeds that competed for land, space, light, nutrients, and water. The pesticides tended to fail as the artificial selection they imposed on their targets promoted the evolution of resistant pests. In the 1960s, herbicides replaced insecticides as the dominant pesticide. Genetic engineered pesticide resistant corn and soybean facilitated the marketing of the generalist herbicides glyphosate, and later dicamba. The genetically engineered crops and pesticide dominate the animal feedstock agriculture in the region. Years of pesticide use have contaminated water, soils, fish and wildlife. The pesticides threaten both human health and that of the environment. Adopting sustainable organic agricultural practices can end the war on nature and help recover the health of the Chesapeake Bay ecosystem and that of its people.

This chapter provides an introduction to the basic science needed for the reader to understand the ensuing chapters that explore the relationship between the health of the Chesapeake Bay, its food system, and the wellbeing of its people. For many readers, high school or college science courses may sit dim in their memories. This chapter will refresh some of those old facts and concepts, as well as introduce some important new ones. It focuses on the most important aspects of physics, chemistry, biology, and ecology needed to understand the subsequent material. Whenever possible the chapters apply the same scientific principles to explain phenomena that are common to human health and that of the Chesapeake Bay Ecosystem.

Captain John Smith and his band of English colonists arrived at the Chesapeake Bay in 1607, discovering an estuary little changed by human activity. This contrasted sharply with the European rivers of that era. The estuaries he knew from England and Europe all suffered from dam-building, overfishing, sedimentation, and pollution. The decedents of the original colonizers, and the many thousands that came subsequently reshaped the Bay by their exploitation of its food resources. Over harvesting, damming of waterways, and oyster reef destruction decimated oysters (Crassostrea virginica) and migratory species of finfish, including; shad (Alosa sapidissima), alewife (Alosa pseudoharengus) blueback herring (Alosa aestivalis) and striped bass (Morone saxatilis). In the twentieth century, application of scientific fisheries methods built around the concept of maximum sustainable yield (MSY) and habitat restoration has yielded only partial recovery of these and other species. Ecosystem based management (EBM) is discussed as a sustainable alternative to MSY that takes into account non-human consumers of the exploited resource. The chapter also reviews the various fishing techniques used on the Bay, including those invented by Native Americans and later methods that facilitated industrial scale harvesting.

To understand the current state of the Chesapeake Bay, its people and food system, and to explore health restoring solutions, it is important to know something about the geological history and physical features of this magnificent ecosystem. This chapter examines how the Bay ecosystem was formed and its main physical features, including those reshaped by human activity. The history of the physical structure of the Chesapeake Bay is driven by geological and atmospheric processes that proceeded over a range of time scales going from thousands to millions of years. However, one seminal event that took place in a matter of minutes about 480 million years ago completely reshaped the Bay. A bolide (exploding meteor) left a crater that reconfigured the drainage of the three most southern tributary rivers and reshaped the mouth of the estuary. Thousands of years of cyclical climate change linked with rising and lowering sea levels transformed the ancient Susquehanna River bed into the modern Chesapeake Bay. This chapter calls on atmospheric science and evolutionary biology to help explain that process. The journey closes with a look at how humans reshaped the physical aspects of the Bay with dams and other features, often in response to the needs of their food systems.

Eutrophication overtook the Chesapeake Bay beginning in the mid twentieth century, and continues to be a major problem. The human food system produces excess inorganic nutrients and oxygen-demanding pollution that are primary drivers in the eutrophication of the Chesapeake Bay. The bulk of that pollution emanates from an agricultural system designed to produce the elements of the Standard American Diet (SAD), including meat and highly refined carbohydrates. Inputs of N and P from modern agriculture’s artificial fertilizers and animal manure, overwhelm the natural, high-fiber inputs of detritus that used to predominate. This results in frequent algal blooms and attendant periods of hypoxia in the bottom waters of the Bay during seasonal stratification. Humans respond to the SAD in a fashion similar to how the Bay responds to the agricultural system that produces the foods for that diet. The excessive biomass of algal blooms is equivalent to the unnecessary and dangerous deposits of adipose that create obesity in people. Hypoxia in the bottom waters of the Bay is analogous to that in the brain and adipose tissues of obese and over-weight people (75% of the Bay’s human population), causing various health problems. Hypoxic bottom waters promote populations of benthic bacteria that release toxic H2S. The high animal component of the SAD produces dysbiosis of the human biome, including bacterial production of disease-promoting H2S in the lower intestines. Both the Bay and humans living there suffer from a lack of fiber-rich organic matter. Reversing eutrophication of the bay and its people requires a shift away from the SAD to a whole food plant based diet.

By the mid-nineteenth century, farmers in the Chesapeake Bay Watershed began importing fertilizers to restore productivity to depleted fields. This began with guano from remote Peruvian shores, which created a market for soil amendments that switched to artificial fertilizer in the twentieth century. The widespread use of artificial fertilizers and animal manures to supply reactive forms of nitrogen to crops resulted in increased productivity per unit area, but also many unintended consequences including; pollution of ground and surface waters, increases in weeds and agricultural pests, air pollution, reduced biodiversity and release of global warming gases. Nitrogen pollution of the Chesapeake Bay caused the onset of persistent eutrophication in the later half of the twentieth century. The USEPA is working with jurisdictions to reduce nitrogen pollution through a series of best management practices that facilitate preserving the current food system while reducing its impact on the environment. Moving the food system away from a focus on animal agriculture and toward producing crops for a whole-food-plant-based-diet will speed the recovery of the Chesapeake Bay ecosystem from the ravages of excessive reactive nitrogen.

Reimagining a new food system for recovering the health of the Chesapeake Bay and its people requires addressing the ethics of the current way we produce and consume food. The present food system is built on making profit with the aid of government subsidies focused on producton of health-damaging animal agriculture. As is the case for most of the US, the Chesapeake Bay region produces more food than it uses, exporting surpluses elsewhere. Consistent surplus production depresses prices. Wealthier farmers take advantage of a system of price supports to sustain their profits. Despite the excess production of food, most of the workers in the food system earn such low wages that they require government subsidized nutrition, organized through the US Department of Agriculture. Many of the lowest paid food system workers are people of color and migrant laborers from Mexico and Central America. Only 7% of the food dollar goes to pay producers, with most of it going to the food service and food processing industries. About 10% of the residents of the Chesapeake Bay region face regular food insecurity and 14% receive subsidized nutrition benefits. The animal product-centered food system pollutes the Chesapeake Bay and sickens its people, while causing the suffering and premature deaths of industrially farmed animals. Extensive use of pesticides and artificial fertilizers on crops grown for animal feed (corn and soy) further degrade the ecosystem. Elements of a new ethical food system include organic production for whole plant based diets, imporved compensation for workers, eliminating the exploitation of animals, developing food literacy, increasing the amount of food prepared at home, replacing corporate profit with social and environmental need as the driving force of agriculture, subsidizing healthy foods, and encouraging local farming with direct distribution to consumers.

Hunting of fowl was a part of the Chesapeake Bay Region’s food system from the earliest times. English colonists introduced the shotgun as an effective weapon against swimming, flying and roosting birds. Despite the new weaponry, populations of game-birds remained fairly abundant for the first century after colonization, since most hunting was for feeding families. The advent of the steamboat and railroad opened up new markets for fowl. These new forms of transportation brought ice for preserving the kill from northern states, and allowed hunters to send the chilled carcasses of slain birds to distant restaurants, hotels, and market centers. The railroads also spurred development of wildlands and the expansion of agriculture, reducing habitat for terrestrial and water birds. The combination of over-hunting and habitat loss drove the nineteenth Century extinction of the passenger pigeon (Ectopistes migratorius), a migratory species which once was the most populous bird in N. America. The loss of the passenger pigeon informed efforts to prevent the same fate befalling widely hunted waterfowl species. Many of the political elite hunted waterfowl and helped push legislation to protect their pastime. This led to the Migratory Bird Treaty Act of 1918, the first national environmental legislation for the US. This act, subsequent legislation, and efforts to recover lost habitat combined to rebuild the populations of most species of waterfowl that frequent the Chesapeake Bay. The Canada goose (Branta canadensis) has gone from near extinction in 1920 to the status of a nuisance species in many locations due to its ability to forage on industrial grain farms. The recovery of other species, such as the canvas back duck (Aythya valisineria) is much less complete. This points to the need to continue tight regulation of hunting and investment in habitat restoration.

The pre-colonial residents of the Chesapeake Bay region developed a sophisticated food system based upon farming, gathering and hunting/fishing. That food system informed all aspects of their lives. The Mesoamerican “three sisters” system of companion farming began to arrive in the region circa 1100 AD. The introduced crops of corn (Zea mays), beans (Phaseolus vulgaris) and squash (Cucurbita sp.) transformed the Algonquin speaking tribes into part-time farmers. The advent of corn disrupted the preceding food system of hunting and gathering. By 1500 AD, corn accounted for half of the Algonquin diet, reducing their dependence on oysters (Crassostrea virginica) and other marine foods. The Algonquin food system relied on fire as a tool to clear lands for farming and hunting, as well as for cooking and making pottery. The widespread use of fire altered the landscape mosaic, leaving plots in various stages of succession. The English colonists that first arrived in 1607 suffered starvation in the winter of 1609–1610 through a combination of bad weather and inability to employ the Algonquin food system. After the colony recovered and was reinforced with new arrivals, it used denial of access to food as a weapon that ultimately rid the colony of all but a few Native American individuals.

Atlantic menhaden Brevoortia tyrannus are an abundant member of the family Clupeidae. This fish is essential to the ecology of the Chesapeake Bay and coastal waters of the Atlantic Ocean, providing the trophic link between plankton and the menhaden’s predators. These predators include the important sportfish striped bass (Morone saxatilis), other game fish, various piscivorous birds, and dolphins. Native Americans and early European colonists harvested the fish on a small scale to manure agricultural fields and feed pigs and chickens. New Englanders brought the menhaden reduction industry to the Chesapeake Bay in the 1870s. This led to the creation of the largest fishery on the East Coast of the US. The inedible menhaden were harvested en masse and processed to yield the commodities of fish meal and fish oil. In the early twentieth Century, fossil fuels took market share from both products, artificial N-fertilizer replacing fish meal, and kerosene replacing menhaden oil. The fish meal and oil became staples for the newly developed industry of concentrated animal feeding operations for chickens and pigs. The late twentieth and early twentyfirst centuries saw another shift in use of these products. Most of the fish meal and some of the oil went as feed to the lucrative and rapidly expanding global animal aquaculture industry. Most of the fish oil went to the new market of dietary supplements for the prevention of heart disease. Despite new evidence questioning the efficacy of fish oil for this medicinal application, the market remains strong. Mid-twentieth Century advances in mechanized harvesting of menhaden contributed to overharvesting that reduced the population well below historical levels. Political pressure from the industry and its allies restrains management measures. Sport fishers and conservationists advocate for reduced fishing pressure. The menhaden reduction industry provides important economic opportunities to a rural region and African American workers. A shift away from the animal product centered standard American diet may reduce the importance of this industry, returning menhaden to its prominent role in the natural food chain of the Chesapeake Bay.

The Chesapeake Bay region was highly involved in the colonial era triangle trade that connected the sugar colonies of the Caribbean to Western Europe and Africa. This brought both sugar and slavery to the Chesapeake. While chattel slavery has passed, virtual slavery to sugar persists as this addictive substance is widely consumed by African Americans and only somewhat less so by others in the Chesapeake region today. The excess calories from added sugars combines with increased consumption of animal products to set up widespread nonalcoholic fatty liver disease (NAFLD) that leads to diabetes and obesity. Per capita annual sugar consumption in the US increased 20-fold between 1820 (3 kg) and 2016 (60 kg). Sweetened beverages, candies and pastries, provide the bulk of added dietary sugars, but 22% is hidden in a large variety of processed foods including soups, meats, prepared meals and condiments. Non-caloric artificial sweeteners also promote weight gain. Retraining the pallets of consumers to accept shifting to a whole-food plant-based diet promises to free the population from type-2 diabetes and other obesity related diseases.

The COVID-19 pandemic has implications for coastal planning and management. Rules for isolation and physical distancing, among other measures for human life protection, have led to the closure of most beaches around the world. The present critical situation has raised the following question: How can some recommendations be designed in sun, sea, and sand tourism-dependent-insular countries to face “the COVID-19 new normality?” We used the content analysis technique to analyze representative publications on a global level to ascertain information on best management practices. A survey of 58 experts provided additional information. We used inferential statistics for sample selection and produced a list of 43 practices and beach planning and management actions to face the COVID-19 pandemic. This led to 27 new recommendations designed for beach planning and management within insular contexts, some of which were tested in the Republic of Cuba. Recommendations aim to guarantee a culture of safety and improvement within the field of beach or coastal planning and management. These recommendations should prove useful for other insular countries, during the COVID-19 period, in the new normality that follows, and in other post-pandemic scenarios.

Emerging research shows adverse health outcomes such as diabetes, obesity, cancer, and neurotoxicity from water pollutants such as flame retardants, endocrine disruptors, and pharmaceuticals. Medical waste and energy use affects water quality and quantity. This chapter provides strategies for health professionals to promote water stewardship at personal, organizational and policy levels. Organizations such as Health Care Without Harm, Alliance of Nurses for Healthy Environments and the Ecology Center offer resources for improving education of health professionals and provide allies for change. Individual advocacy through writing op-eds, policy briefs, meeting with legislators and participation in coalitions allows health professionals to interpret the science behind the need for policy changes. Recommendations for health care curricula prepare students to develop sustainable practices through inter-professional collaboration. Environmentalists can use this information to better engage health professionals in promoting change.

This paper describes a course focused on renewable energy developed to teach college-level students about the application of geoscience principles that underlie sustainable technologies, the implementation of these technologies, and their societal context. The 11-module Renewable Energy and Environmental Sustainability course uses hands-on, active learning techniques to engage students in data acquisition and analysis. The modules may be taught in their entirety as a complete course or used individually to supplement offerings such as in a general environmental science class. The chapter provides guidance in using the open-access online materials for implementing the course, including a discussion of pedagogy, how to use the supplied learner-centered activities, and assessment tools. The chapter recounts some of the key experiences of professors who piloted the course at three universities. Pre- and post-course assessments documented the improvement of student knowledge and an increased proclivity to include environmental sustainability in their decisions regarding careers and lifestyle choices.

This chapter provides information on the fundamental concepts needed to understand water and water pollution, enabling better comprehension of the subsequent material. Examining the molecular structure of water provides context for understanding its most important properties. The reader explores the various types of natural waters and learns how they are tied together in the global water cycle. An examination of the contents of natural waters reveals the presence of dissolved solids, liquids and gases and the intimate relationship between these substances and the community of life that dwells in aquatic systems. The chapter introduces basic concepts of the chemistry of water and discusses the action and distribution of pollutants. Readers also learn about the basic interaction between various pollutants and the aquatic food chain.

Two different habitats in the Chesapeake Bay were tested for the occurrence of diel vertical migration (DVM) by members of the zooplankton community. During July of 1997 diel samples were collected from Jones Creek, a small, protected, 3-m deep tidal gut, and a station in Hampton Roads, a 20-m deep, expansive section of the bay. Temperature, salinity, light penetration, water clarity, dissolved oxygen, total particulate nitrogen and carbon, chlorophyll concentration, and algal density were also determined for depth increments at these stations, ca. midday and midnight. Significant differences in zooplankton depth distribution occurred over the day at both stations. The calanoid copepod,Acartia tonsa, dominated the zooplankton community and the larger stages were strong migrators. Mysid shrimp, the largest sized crustaceans, displayed significant DVM at both stations. Although diel differences were also detected in chlorophylla concentrations, with 25% reduction at night in Jones Creek and 18% in Hampton Roads, counts of algal cells revealed no differences between night and day numbers. The nightly losses of chlorophyll were not driven by mesozooplankton grazers. Using grazing rates from the literature, we estimated that mesozooplankton harvested less than 5% of the standing crop of phytoplankton each day in both locations. Food quantity and quality (as determined by chlorophyll concentrations, cell counts, and C:N ratio) were uniform in the Jones Creek water column, but higher near the surface in Hampton Roads. While it was clearly advantageous for zooplankton to migrate to surface waters at night for feeding in Hampton Roads, it is paradoxical for DVM to persist in Jones Creek when ample food was found in deeper water.

The ocean science and policy communities articulate two prevailing arguments to encourage changes in human behavior that will result in conservation of marine biological diversity. The first is utilitarian and includes encouraging the sustainable use of exploited ocean resources (i.e., prudent use of the public commons) and conserving particular attributes of the environment that provide ecosystem services such as processing wastes from human activities. The other is ethical and includes valuing biological diversity for its inherent properties and believing in its conservation for its own sake. Are these two approaches alone sufficient to build the social consensus needed to alter human behavior and implement programs to preserve and restore the world's oceans? Fil: Auster, Peter J.. University of Connecticut; Estados Unidos Fil: Fujita, Rod. No especifíca; Fil: Kellert, Stephen R.. University of Yale; Estados Unidos Fil: Avise, John. University of California at Irvine; Estados Unidos Fil: Campagna, Claudio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Wildlife Conservation Society; Estados Unidos Fil: Cuker, Benjamin. Hampton University; Estados Unidos Fil: Dayton, Paul. University of California at San Diego; Estados Unidos Fil: Heneman, Burr. No especifíca; Fil: Kenchington, Richard. University Of Wollongong; Australia Fil: Stone, Greg. New England Aquarium; Estados Unidos Fil: Notarbartolo Di Sciara, Giuseppe. Tethys Research Institute; Italia Fil: Glynn, Polita. Pew Fellows Program In Marine Conservation; Estados Unidos

This paper explores how suspended clays alter the trophic interactions that govern composition and density of the zooplankton community in a small eutrophic North Carolina (USA) lake. Enclosures (12 M3) were used in a complete, triplicated, cross-classified design. The four treatments were; BASS (1 piscivorous fish/enclosure), BASS + CLAY, SUNFISH (16 planktivorous fish/enclosure), SUNFISH + CLAY. The +CLAY treatments received 100 g.m-2 d-l of montmorillonitic clay. It was anticipated that turbidity from clay would release crustacean zooplankton from visual planktivores. Contrary to this ex- pectation, crustacean zooplankton populations in the SUNFISH + CLAY were fourfold less than in the SUNFISH treatment. The reduction was not linked to deleterious effects of clay, since zooplankton populations were higher in the BASS + CLAY than the BASS treatment. Instead, crustacean zooplankton appeared to be governed primarily by Chaobo- rus predation. Suspended clay weakened the link between visually predaceous fish and Chaoborus, which in turn strengthened the effect of Chaoborus predation on crustacean zooplankton. Since fish selectively cropped larger instars of Chaoborus, rotifers (primarily Keratella cochlearis), which are mostly eaten by smaller instars of Chaoborus, were unaf- fected by clay.

The effects on zooplankton community structure of P loading and two different kinds of suspended sediments were tested in a small lake. Limnocorrals were used in a complete, triplicated, sixtreatment-block design. Treatments were loading with P, kaolinitic clay (IQ, K+P, montmorillonitic clay (M), and M+P plus a control without additions. P fertilization caused blooms of blue-green bacteria and resulted in reductions of the dominant copepod (Diaptomus mississippiensis) and cladocerans (Diaphanosoma brachyurum, Bosmina longirostris, and Ceriodaphnia reticulata), while causing a 5-fold increase in rotifers (mostly Keratella cochlearis). Zooplankton in the K and K+P treatments were similar to the control, but cladoceran species other than Diaphanosoma were reduced. M was more detrimental to zooplankton than K, causing a lo-fold decrease for all crustaceans. We attribute this in part to lower algal densities in the A4 treatment. Simultaneous P loading mitigated the effects of M on Diaphanosoma, rotifers, and copepods and may involve a transfer loop in which dissolved organic C adsorbed on clay becomes available to filter-feeding zooplankton. The effects of mineral turbidity apparently cascaded up the food chain, with both kinds of clays reducing densities of Chaoborus larvae.

Enclosures in a small piedmont reservoir in the southeastern United States were used to determine the effects of loading by phosphate and two clay sediments on periphyton community structure and production during the summer growing season. The experimental design included replicated controls and the following treatments added at 2-to 3-day intervals: phosphate (PHOS), kaolinite (KAOL), montmorillonite (MONT), kaolinite with phosphate (K+P), and montmorillonite with phosphate (M+P). Periphyton were sampled from polyethylene strips of the same material as the enclosure walls, suspended at depths of 0.5 m and 2.0 m to assess treatment effects on shallow (epilimnetic) vs. deep (hypolimnetic) communities. Colonization after 40 days was sparse, dominated in biovolume by blue-green algae in all but the epilimnion of controls, in which small gelatinous green algae and chrysophyte flagellates were abundant. The biovolume of shallow periphyton after 79 days was lowest in KAOL and MONT, intermediate in controls and PHOS, and greatest in clay + P. Hence, P enrichment alleviated the deleterious effects of clay on periphyton production, and clay + P appeared to act synergistically in stimulating benthic algal growth. Periphyton biovolume was comparable among shallow and deep controls, PHOS, and treatments with the rapidly settling kaolinite. Lowest biovolume occurred at depth in treatments with montmorillonite under extreme light attenuation imposed by the suspended, finely particulate clay. The relative contribution of blue-green algae to total periphyton production was highest in clay + P treatments and lowest in controls. Heterotrophic dinoflagellates increased in the shallow periphyton under clay loading, and in the deep communities under PHOS and M + P. Periphyton contributed only 20–32% of total mesocosm productivity in controls, PHOS, and KAOL, increasing to about 40% in MONT, and to 72–91% of the total in M + P and K + P. The data indicate that benthic microalgae can represent a major proportion of the primary production in shallow reservoirs under high phosphate and sediment loading.

The effects on phytoplankton and limnetics of two different types of suspended sediments and their interactions with P loading were tested in a small North Carolina Piedmont lake. Limnocorrals were used in a complete, triplicated six-treatment, blocked design. Treatments were loaded with P, kaolinitic clay (K), K+P, montmorillonitic clay (M), and M+P. A4 caused more turbidity and stayed in suspension longer than K. Consequently, the light-dependent parameters, net community productivity (NCP), chlorophyll concentration, and algal density were lowest in the M and highest in the P treatment. Combined P and clay loading promoted clearing for both sediments and mitigated their effects on algal densities and NCP. Flagellated algae and nonfilamentous cyanophytes dominated the control community. The P treatment had blooms ofAnabaena. Without fertilization, both clays resulted in sparse, flagellate-dominated communities. The M+P community, like that of the P treatment, was dominated by Anabaena, but total algal densities were suppressed. In contrast, the K-t-P community lacked Anabaena and was similar to the control in algal quantity and composition. Various mineral substances cause turbidity in lakes, including clays of distinct mineralogies from eroding soils, resuspended bottom sediments, glacial flours, and calcite precipitates. It is unlikely that such a heterogeneous array could exert uniform influences on lacustrine systems. Differential composition of suspensions may be a source of some of the conflict among investigators’ of the effects of mineral turbidity. Some studies show mineral turbidity to favor flagellated algae at the expense of filamentous blue-greens (Hergenrader and Hammer 1971; Avnimelech et al. 1982; Cuker 1987), yet other contrasting reports link blooms of these filamentous blue-greens to loading with suspended clays (Carriker and Taylor 1984; Hart 1987). The effects of mineral turbidity

We tested the role of the slimy sculpin (Cottus cognatus), a benthic fish, in structuring the rocky littoral invertebrate community in Toolik Lake, Alaska. Comparisons of sculpin gut contents and prey community structure indicated that these fish forage selectively, eating proportionally more large and motile prey, and proportionally fewer small and sessile forms. Field experiments compared the effects of natural, reduced and elevated sculpin densities on benthic community structure. At natural levels of sculpin density, biomass of trichopteran larvae were reduced by more than 50%, and predatory chironomid larvae by 27%, in comparison to areas where sculpin were excluded. Tube-dwelling and small free living chironomid larvae were unaffected at normal sculpin densities. Under artificially high sculpin densities, there was some reduction of tube-dwelling chironomids, but the small free living ones remained unaffected. There appears to be a threshold length of about 3.5 mm, below which chironomid larvae are free form sculpin predation. Tube-dwelling chironomids may be longer than this threshold, but still avoid predation by having most of their body hidden in their tubes.

Independent and interactive effects of phosphorus and clay loading on pelagic community organization and productivity were tested in a small piedmont lake in North Carolina. Twelve limnocorrals (2-m diam, 3 m deep) were used for field manipulations. Treatments (in triplicate) were unaltered controls, P loading of 3.3 mg m−2 d−1, kaolinite clay loading of 100 g m−2 d−1, and combined clay and P loading. Fertilization with P significantly increased rates of turbidity reduction in comparison to controls (Secchi depth increasing at 7.2 vs. 5.8 cm d−1) and also significantly lowered sustained turbidity in treatments under clay loading. Clay loading reduced net community productivity (NCP), Chl a concentrations, and algal cell numbers. Suspended clay also caused a shift in algal community composition; Trachelomonas superba and other flagellates replaced the otherwise dominant blue-green Spirulina major. Fertilization with P increased NCP and algal densities and favored development of the N2-fixing blue-green algae Anabaena spiroides and Anabaena circinalis. Combined P and clay loading produced intermediate values of turbidity, NCP, and Chl a. Simultaneous clay loading eliminated the influence of P fertilization on algal community structure, yielding an assemblage dominated by flagellates. Clay turbidity also caused a shallowing in the daytime distribution of zooplankton.

During 1977, the population density of Hydra in the rocky littoral community in Toolik Lake, Alaska, increased from June to a maximum in late July or early August, then remained stable or decreased slightly through late August. The summer increase of Hydra corresponded to increases in the availability of copepods and Bosmina (the preferred prey) until late July. Hydra kept at lake temperatures in the laboratory with unlimited prey reproduced fast enough asexually to account for these increases: at 19°C the intrinsic rate of increase (r, biomass) was 0.53 g·g‒1·d‒1, and at 11°C, r = 0.31·d‒1. These rates, much higher than those for other Hydra at comparable temperatures, seem to be a metabolic adaptation to arctic conditions. Failure of the Hydra population to continue to increase while food resources increased in August is attributed to predation by Lymnaea, displacement by epilithic algal growth, endogenously controlled emigration from the rocky littoral, or some combination of these. Hydra appears to be the most important predator on Bosmina. Hydra at densities of 135·m‒2 on the rocky shoals could take 1,620 Bosmina · m‒2·d−1 during late July and early August 1977, about 10% per day consumption of the estimated lake standing crop of Bosmina. This is the first evidence that Hydra plays a major role in controlling a prey population.

Slimy sculpins (Cottus cognatus) were caught in the littoral region of Toolik Lake, an arctic lake. These sculpins grew slower and lived longer (71 mm at 8+ years) than more southerly populations. Sculpin distribution along the slope of the rocky littoral zone was greatest at the 3.5 m depth and coincided with the rock-mud interface. The hypothesis that this ‘preferred’ area provided both increased prey and reduced predation was advanced. Yearly production estimate of littoral sculpins was 0.40 g · m−2 · yr−1 with a P/B ratio of 0.36. This is considerably less than estimates for more southerly populations of the same species.

Effects of the grazing activity of the gastropod Lymnaea elodes (arctica?) on animal community structure in the rocky littoral of an arctic lake were examined. In situ caging experiments on natural substrates with various snail densities resulted in shifts in faunal biomass abundance and distribution. Chironomids living in fixed tubes (Paratanytarsus) were greatly reduced at high snail loads. Free—living scrapers (Corynoneura, Crictopus cf. sylvestris, Zalutschia trigonocies, and others) fared only slightly better, while predators (Arctopelopia and Ablabesmyia) were relatively less sensitive to changes in snail density. Trichoptera larvae, Acari, and copepods were unaffected by the snails. Ostracoda and Cladocera biomass was significantly reduced by Lymnaea. All of the less sensitive groups were relatively more mobile. Reduced algal biomass and chlorophyll concentration were correlated with increased snail densities. Lymnaea production was limited by conspecific density and food. See full-text article at ...