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In the Northern Alboran Sea, artisanal small-scale fisheries using trammel nets suffer economic losses, and local fishermen see their way-of-life endangered, due to interactions with wildlife species such as alien species and dolphins. On the one hand, the alien seaweed Rugulopteryx okamurae, which was first recorded in the Alboran Sea in 2015, has undergone an intensive expansion in the sub-region, monopolizing the available seabed, causing radical changes in the underwater seascape and clogging the trammel nets. On the other hand, the damage caused to the fishing nets by dolphin fish predation is an ancient problem worldwide, but it is intensifying in the last years. The main objective of this study is to understand the main environmental and technical conditions that favor damages of fishing trammel nets in the Alboran Sea, which entails an important loss of catchability, due to (i) the clogging of the artisanal fishing trammel nets by invasive seaweed, and (ii) the breaking of the nets by dolphin predation. Through close monitoring of fishermen in port, we obtained direct information of 548 sets. Our results indicate that approximately 30% of trammel sets suffered a damage due to unwanted interaction with alien seaweeds and dolphins. As seaweeds invasion is a global problem while dolphin-fishing gear interaction is more local, we concluded that only a large-scale management of exotic algae, together with the involvement of local fishermen, could solve the economic problems of this activity.

Blooms of toxic or harmful microalgae, commonly called "red tides," represent a significant and expanding threat to human health and fisheries resources throughout the United States and the world. Ecological, aesthetic, and public health impacts include: mass mortalities of wild and farmed fish and shellfish, human intoxication and death from the consumption of contaminated shellfish or fish, alterations of marine food webs through adverse effects on larvae and other life history stages of commercial fish species, the noxious smell and appearance of algae accumulated in nearshore waters or deposited on beaches, and mass mortalities of marine mammals, seabirds, and other animals. In this report, we provide an estimate of the economic impacts of HABs in the United States from events where such impacts were measurable with a fair degree of confidence during the interval 1987-92. The total economic impact averaged $49 million per year, with public health impacts representing the largest component (45 percent). Commercial fisheries impacts were the next largest (37 percent of the total), while recreation/tourism accounted for 13 percent, and monitoring/management impacts 4 percent. These estimates are highly conservative, as many economic costs or impacts from HABs could not be estimated., Funding was provided by the National Oceanic and Atmospheric Administration under Grants No. NA46RG0470 and NA90AA-D-SG480, the National Science Foundation under Grant No. OCE-9321244, and the Johnson Endowment of the Marine Policy Center.

Blooms of toxic or harmful microalgae, commonly called "red tides," represent a significant and expanding threat to human health and fisheries resources throughout the United States and the world. Ecological, aesthetic, and public health impacts include: mass mortalities of wild and farmed fish and shellfish, human intoxication and death from the consumption of contaminated shellfish or fish, alterations of marine food webs through adverse effects on larvae and other life history stages of commercial fish species, the noxious smell and appearance of algae accumulated in nearshore waters or deposited on beaches, and mass mortalities of marine mammals, seabirds, and other animals. In this report, we provide an estimate of the economic impacts of HABs in the United States from events where such impacts were measurable with a fair degree of confidence during the interval 1987-92. The total economic impact averaged $49 million per year, with public health impacts representing the largest component (45 percent). Commercial fisheries impacts were the next largest (37 percent of the total), while recreation/tourism accounted for 13 percent, and monitoring/management impacts 4 percent. These estimates are highly conservative, as many economic costs or impacts from HABs could not be estimated., Funding was provided by the National Oceanic and Atmospheric Administration under Grants No. NA46RG0470 and NA90AA-D-SG480, the National Science Foundation under Grant No. OCE-9321244, and the Johnson Endowment of the Marine Policy Center.

Blooms of toxic or harmful microalgae, commonly called "red tides," represent a significant and expanding threat to human health and fisheries resources throughout the United States and the world. Ecological, aesthetic, and public health impacts include: mass mortalities of wild and farmed fish and shellfish, human intoxication and death from the consumption of contaminated shellfish or fish, alterations of marine food webs through adverse effects on larvae and other life history stages of commercial fish species, the noxious smell and appearance of algae accumulated in nearshore waters or deposited on beaches, and mass mortalities of marine mammals, seabirds, and other animals. In this report, we provide an estimate of the economic impacts of HABs in the United States from events where such impacts were measurable with a fair degree of confidence during the interval 1987-92. The total economic impact averaged $49 million per year, with public health impacts representing the largest component (45 percent). Commercial fisheries impacts were the next largest (37 percent of the total), while recreation/tourism accounted for 13 percent, and monitoring/management impacts 4 percent. These estimates are highly conservative, as many economic costs or impacts from HABs could not be estimated., Funding was provided by the National Oceanic and Atmospheric Administration under Grants No. NA46RG0470 and NA90AA-D-SG480, the National Science Foundation under Grant No. OCE-9321244, and the Johnson Endowment of the Marine Policy Center.