Aquaculture risk management and marine mammal interactions in the Pacific Northwest

Nash, Colin E.; Iwamoto, Robert N.; Mahnken, Conrad V. W.

doi:10.1016/s0044-8486(99)00300-2

Cited by 59 publications

(63 citation statements)

References 8 publications

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“…Predatory fish and mammals have also been observed in farm surroundings predating on both the cultured and attracted fish (Nash et al 2000, Sepulveda & Oliva 2005. Furthermore, the input of particulate waste to the sediments attracts benthic fish and stimulates the productivity of benthic fauna and epifauna, providing food for benthic fish (Kutti et al 2007b).…”

Section: Interactions With Wild Fish and Predatorsmentioning

confidence: 99%

“…On the Pacific coast of the USA and Canada, sea lions and harbor seals interact with coastal fish farms by predating upon salmonids inside the cages while damaging netting in the process (Nash et al 2000). On the Atlantic coast, harbor seals and grey seals pose similar problems (Nash et al 2000), and in Chile, negative interactions of sea lions with salmon farms have been described (Sepulveda & Oliva 2005). Moving farms offshore could attract larger and more abundant predators to the farms, including species such as sharks and killer whales.…”

Section: Interactions With Wild Fish and Predatorsmentioning

confidence: 99%

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Environmental issues of fish farming in offshore waters: perspectives, concerns and research needs

Holmer¹

2010

Aquacult. Environ. Interact.

253

195

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Offshore fish farming is predicted to increase in the near future driven by the lack of coastal space. In this review I discuss the environmental issues of offshore farming from experience in coastal farms. Even more so than in coastal farms, a rapid and wide dispersal of dissolved waste products is predicted for offshore farms. Despite wider dispersal of particulate waste products, fast sinking rates of feed pellets and faeces suggest organic enrichment of the bottom sediments in farm vicinities (hundreds of meters), although at lower loading rates than coastal farms. The benthic response to organic enrichment is unpredictable due to lack of knowledge from shelf areas. Most shelf sediments are considered carbon limited and fish farm waste products may stimulate the benthic communities, but due to the sparse abundance and absence of pollutant-tolerant benthic fauna, the capacity of benthic communities to assimilate organic matter may be limited. Instead, microbial decomposition of waste products could become important, leading to increased oxygen demand and accumulation of sulfides in the sediments. This may negatively affect benthic biodiversity. Interactions with wild fish (aggregation, genetic impacts, spreading of disease and parasites) are expected, but difficult to predict, as the composition of species attracted to offshore farms will be different from that of species attracted to coastal farms. Escapees are potentially a high risk due to farm failure under rough weather conditions in the open sea. The carbon footprint of farming offshore will increase (transportation) and the ecological footprint (fishing feed) will remain a severe constraint, as in coastal farming. Offshore farming is subject to high costs of operation, including those for monitoring environmental conditions. Research should focus on interactions with wild fish populations, mapping of sensitive benthic habitats and experimental studies of the response of benthic habitats to organic enrichments.

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Section: Interactions With Wild Fish and Predatorsmentioning

confidence: 99%

Section: Interactions With Wild Fish and Predatorsmentioning

confidence: 99%

Environmental issues of fish farming in offshore waters: perspectives, concerns and research needs

Holmer¹

2010

Aquacult. Environ. Interact.

253

195

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“…In general, these fish farms tend to attract a greater range of predator species than closed, land-based systems or freshwater systems (Beveridge 1996). Predation on fish farms results in death and injury to fish, and reported economic damage to the industry in many parts of the world can be substantial (Adámek et al 2003;Nash et al 2000;Sepùlveda and Oliva 2005).…”

Section: Predatorsmentioning

confidence: 99%

Animal Welfare and Organic Aquaculture in Open Systems

Cottee

Petersan

2009

J Agric Environ Ethics

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The principles of organic farming espouse a holistic approach to agriculture that promotes sustainable and harmonious relationships amongst the natural environment, plants, and animals, as well as regard for animals' physiological and behavioral needs. However, open aquaculture systems-both organic and conventional-present unresolved and significant challenges to the welfare of farmed and wild fish, as well as other wildlife, and to environmental integrity, due to water quality issues, escapes, parasites, predator control, and feed-source sustainability. Without addressing these issues, it is unlikely that open net-pen aquaculture production can be compatible with the principles inherent to organic farming.

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“…They can consume stocks or catch directly, inflict harm upon the catch and the fishing gear, introduce fecal coliform bacteria or parasites, and become severely or fatally caught in the gear (reviewed in Hammond & Fedak, 1994;Dawson et al, 1998;Nash et al, 2000). These interactions should be limited both to protect the animals and to reduce the economic losses incurred by the fisheries.…”

Section: A62 Introductionmentioning

confidence: 99%

Orchestration : the movement and vocal behavior of free-ranging Norwegian killer whales (Orcinus orca)

Shapiro¹

2008

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Studying the social and cultural transmission of behavior among animals helps to identify patterns of interaction and information content flowing between individuals. Killer whales are likely to acquire traits culturally based on their population-specific feeding behaviors and group-distinctive vocal repertoires. I used digital tags to explore the contributions of individual Norwegian killer whales to group carousel feeding and the relationships between vocal and non-vocal activity.Periods of tail slapping to incapacitate herring during feeding were characterized by elevated movement variability, heightened vocal activity and call types containing additional orientation cues. Tail slaps produced by tagged animals were identified using a rapid pitch change and occurred primarily within 20m of the surface. Two simultaneously tagged animals maneuvered similarly when tail slapping within 60s of one another, indicating that the position and composition of the herring ball influenced their behavior.Two types of behavioral sequence preceding the tight circling of carousel feeding were apparent. First, the animals engaged in periods of directional swimming. They were silent in 2 of 3 instances, suggesting they may have located other foraging groups by eavesdropping. Second, tagged animals made broad horizontal loops as they dove in a manner consistent with corralling. All 4 of these occasions were accompanied by vocal activity, indicating that this and tail slapping may benefit from social communication. No significant relationship between the call types and the actual movement measurements was found.Killer whale vocalizations traditionally have been classified into discrete call types. Using human speech processing techniques, I considered that calls are alternatively comprised of shared segments that can be recombined to form the stereotyped and variable repertoire. In a classification experiment, the characterization of calls using the whole call, a set of unshared segments, or a set of shared segments yielded equivalent performance. The shared segments required less information to parse the same vocalizations, suggesting a more parsimonious system of representation.This closer examination of the movements and vocalizations of Norwegian killer 3 whales, combined with future work on ontogeny and transmission, will inform our understanding of whether and how culture plays a role in achieving population-specific behaviors in this species. 4 ACKNOWLEDGEMENTS

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Aquaculture risk management and marine mammal interactions in the Pacific Northwest

Cited by 59 publications

References 8 publications

Environmental issues of fish farming in offshore waters: perspectives, concerns and research needs

Environmental issues of fish farming in offshore waters: perspectives, concerns and research needs

Animal Welfare and Organic Aquaculture in Open Systems

Orchestration : the movement and vocal behavior of free-ranging Norwegian killer whales (Orcinus orca)

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