Porter Hoagland

The Economic Effects of Harmful Algal Blooms

Much work remains to develop reliable estimates of the economic effects of HABs. As this work proceeds, attention should be directed at the rationale for developing these estimates. While government officials and others might solicit economic estimates of any kind in order to justify idiosyncratic public health or scientific agendas, attention should be directed at developing estimates of true economic losses, i.e., surplus changes. Based upon our experience with the field, although the number of studies of economic losses or impacts is limited, they outnumber studies of the economic costs of societal responses to HAB events. In other words, societal responses to HABs have been debated, formulated, and implemented with an inadequate understanding of the net benefits of such responses. Further efforts on the economics of HABs should focus on identifying the array of societal responses and characterizing the cost minimizing combination of management actions.

Anthropogenic nutrients and harmful algae in coastal waters

Harmful algal blooms (HABs) are thought to be increasing in coastal waters worldwide. Anthropogenic nutrient enrichment has been proposed as a principal causative factor of this increase through elevated inorganic and/or organic nutrient concentrations and modified nutrient ratios. We assess: 1) the level of understanding of the link between the amount, form and ratio of anthropogenic nutrients and HABs; 2) the evidence for a link between anthropogenically generated HABs and negative impacts on human health; and 3) the economic implications of anthropogenic nutrient/HAB interactions. We demonstrate that an anthropogenic nutrient-HAB link is far from universal, and where it has been demonstrated, it is most frequently associated with high biomass rather than low biomass (biotoxin producing) HABs. While organic nutrients have been shown to support the growth of a range of HAB species, insufficient evidence exists to clearly establish if these nutrients specifically promote the growth of harmful species in preference to benign ones, or if/how they influence toxicity of harmful species. We conclude that the role of anthropogenic nutrients in promoting HABs is site-specific, with hydrodynamic processes often determining whether blooms occur. We also find a lack of evidence of widespread significant adverse health impacts from anthropogenic nutrient-generated HABs, although this may be partly due to a lack of human/animal health and HAB monitoring. Detailed economic evaluation and cost/benefit analysis of the impact of anthropogenically generated HABs, or nutrient reduction schemes to alleviate them, is also frequently lacking.

The costs of respiratory illnesses arising from Florida Gulf Coast Karenia brevis blooms

Background Algal blooms of Karenia brevis, a harmful marine algae, occur almost annually off the west coast of Florida. At high concentrations, K. brevis blooms can cause harm through the release of potent toxins, known as brevetoxins, to the atmosphere. Epidemiologic studies suggest that aerosolized brevetoxins are linked to respiratory illnesses in humans. Objectives We hypothesized a relationship between K. brevis blooms and respiratory illness visits to hospital emergency departments (EDs) while controlling for environmental factors, disease, and tourism. We sought to use this relationship to estimate the costs of illness associated with aerosolized brevetoxins. Methods We developed a statistical exposure–response model to express hypotheses about the relationship between respiratory illnesses and bloom events. We estimated the model with data on ED visits, K. brevis cell densities, and measures of pollen, pollutants, respiratory disease, and intra-annual population changes. Results We found that lagged K. brevis cell counts, low air temperatures, influenza outbreaks, high pollen counts, and tourist visits helped explain the number of respiratory-specific ED diagnoses. The capitalized estimated marginal costs of illness for ED respiratory illnesses associated with K. brevis blooms in Sarasota County, Florida, alone ranged from

Science and Economics in the Management of an Invasive Species

0.5 to

The Optimal Allocation of Ocean Space: Aquaculture and Wild-Harvest Fisheries

4 million, depending on bloom severity. Conclusions Blooms of K. brevis lead to significant economic impacts. The costs of illness of ED visits are a conservative estimate of the total economic impacts. It will become increasingly necessary to understand the scale of the economic losses associated with K. brevis blooms to make rational choices about appropriate mitigation.

Economic Activity Associated with the Northeast Shelf Large Marine Ecosystem: Application of an Input-Output Approach

ABSTRACT Estimates of the economic impacts of nonnative nuisance (“invasive”) species must rely on both a sound ecological understanding and the proper application of economic methods. Focusing on the example of the invasive European green crab (Carcinus maenas), we show that the crabs estimated economic impact—which has been used to help justify recent public policy—is based on data taken from the wrong geographic location. Furthermore, the predictions of ecological effects appear to rest on loose footing, and economic methods have been misapplied in constructing the estimate. Our purpose is to call attention to the need for the more careful application of science and economics in managing this pressing environmental issue.

A Bioeconomic Analysis of Traditional Fisheries in the Red Sea

A significant problem hindering the emergence or the continued growth of aquaculture in many marine areas is the conflict that arises among it and other ocean uses. We develop a framework to clarify the choice of the optimal scale of aquaculture when that use impacts a commercial fishery. We identify a range of potential impacts, both positive and negative, and analyze how one or more might affect the carrying capacity of a fish stock. We conduct a numerical simulation to illustrate a case where aquaculture and fishery uses interact in the ocean and compete in the product market, and we find that an ocean area could be devoted exclusively to aquaculture. This result depends strongly upon assumptions about the nature of the interaction, the geographic distribution of fish, and the aquaculture production technology. We also investigate the behavior of the model when both uses are able to coexist.

The human health effects of Florida Red Tide (FRT) blooms: An expanded analysis

Abstract The industries linked to the uses of a large marine ecosystem (LME) have a substantial influence on contiguous coastal economies. We estimate the economic activity of U.S. marine sectors associated with the Northeast Shelf LME. Our best upper bound estimate of total output impact is

RISK ASSESSMENT IN OPEN-OCEAN AQUACULTURE: A FIRM-LEVEL INVESTMENT-PRODUCTION MODEL

339 billion, including a total “value-added” impact of

Manganese nodule price trends: Dim prospects for the commercialization of deep seabed mining

209 billion. Total employment impacts are estimated on the order of 3.6 million persons. The estimate of total value-added impact is approximately 10% of the