scholarly journals Examining the Role of Marine Mammals and Seabirds in Southeast Alaska’s Marine Ecosystem Dynamics

2021 ◽  
Vol 8 ◽  
Author(s):  
Melissa Rhodes-Reese ◽  
David Clay ◽  
Curry Cunningham ◽  
Janet Moriles-Miller ◽  
Cheryl Reese ◽  
...  
Keyword(s):  
Nutrient Cycling ◽  
Fisheries Management ◽  
Marine Mammal ◽  
Marine Mammals ◽  
Marine Ecosystem ◽  
Climatic Conditions ◽  
Ecosystem Dynamics ◽  
Nutrient Concentrations ◽  
Nutrient Sources

Primary producers are the foundation of marine food webs and require reliable nutrient sources to maintain their important role with ecosystems. While marine mammals and seabirds can play critical roles in marine nutrient cycling, their contributions are often overlooked. Southeast Alaska’s marine environment supports abundant marine mammal and seabird populations in addition to valuable fisheries. Nonetheless, there is still relatively little known about nutrient sources and fluxes in this region which is a critical component of fisheries management. The goal of our study was to advance knowledge of the role of mammals and seabirds in marine nutrient cycling and to understand how changing marine mammal and seabird populations may alter ecosystem dynamics. We utilized qualitative network models (QNMs) to examine how a simulated Southeast Alaska ecosystem would respond to an increase in marine mammals, seabirds, and nutrients. Researchers are increasingly utilizing QNMs as a first step in the development of ecosystem-based fisheries management plans as their adaptable nature is well suited to address rapidly changing climatic conditions. Our results indicate that marine mammals and seabirds make important contributions to marine nutrient concentrations in the region and that these valuable ecosystem services should not be overlooked.

scholarly journals Ecosystem-Based Fisheries Management, Commercial Fisheries, Marine Mammals and the 2001 Reykjavik Declaration in the Context of International Law

2002 ◽  
Vol 17 (4) ◽  
pp. 561-595 ◽  
Author(s):  
Erik Jaap Molenaar
Keyword(s):  
Fisheries Management ◽  
Marine Mammals ◽  
Legal Status ◽  
Marine Ecosystem ◽  
Commercial Fisheries ◽  
Positive Effects ◽  
Legal Constraints ◽  
Definition Of ◽  
Ecosystem Based Fisheries Management

AbstractThe current global crisis in marine capture fisheries contrasts sharply with the recovery of some stocks of marine mammals. Eventually this will have to lead to a re-evaluation of the preferential treatment that marine mammals now often enjoy. The widening support for ecosystem-based fisheries management (EBFM) and the growing insight in the interactions between marine mammals and commercial fisheries are expected to influence this evaluation. This article examines the role of marine mammals in the ecosystem with special emphasis on predation on commercial fisheries. Ample attention is devoted to the definition of EBFM, its legal status and issues of implementation. The 2001 Reykjavik Declaration on Responsible Fisheries in the Marine Ecosystem is used for illustration. One of the conclusions is that sufficient scientific research is required to substantiate positive effects that pre-emptive catches of marine mammals would have for (recovering) commercial fisheries. The regulatory objectives and international legal constraints relevant to marine mammals are moreover addressed to determine if the exploitation of marine mammals could be obligatory or "necessary".

scholarly journals Causes and consequences of marine mammal population declines in southwest Alaska: a food-web perspective

2009 ◽  
Vol 364 (1524) ◽  
pp. 1647-1658 ◽  
Author(s):  
J.A. Estes ◽  
D.F. Doak ◽  
A.M. Springer ◽  
T.M. Williams
Keyword(s):  
World War Ii ◽  
Marine Mammal ◽  
Marine Mammals ◽  
Marine Ecosystem ◽  
Kelp Forests ◽  
Sea Otter ◽  
Population Declines ◽  
Killer Whales ◽  
Sea Otters ◽  
Coastal Marine

Populations of sea otters, seals and sea lions have collapsed across much of southwest Alaska over the past several decades. The sea otter decline set off a trophic cascade in which the coastal marine ecosystem underwent a phase shift from kelp forests to deforested sea urchin barrens. This interaction in turn affected the distribution, abundance and productivity of numerous other species. Ecological consequences of the pinniped declines are largely unknown. Increased predation by transient (marine mammal-eating) killer whales probably caused the sea otter declines and may have caused the pinniped declines as well. Springer et al . proposed that killer whales, which purportedly fed extensively on great whales, expanded their diets to include a higher percentage of sea otters and pinnipeds following a sharp reduction in great whale numbers from post World War II industrial whaling. Critics of this hypothesis claim that great whales are not now and probably never were an important nutritional resource for killer whales. We used demographic/energetic analyses to evaluate whether or not a predator–prey system involving killer whales and the smaller marine mammals would be sustainable without some nutritional contribution from the great whales. Our results indicate that while such a system is possible, it could only exist under a narrow range of extreme conditions and is therefore highly unlikely.

scholarly journals The role of the coastal communities as first responders of stranded marine mammals in East Java

2018 ◽  
Vol 73 ◽  
pp. 02006
Author(s):  
Achmadah Kurniawati ◽  
Jafron Wasiq Hidayat
Keyword(s):  
Marine Mammal ◽  
Marine Mammals ◽  
First Responders ◽  
Coastal Communities ◽  
Risk Of Death ◽  
Risk Of Disease

Marine mammals in Indonesia mainly consisting of whales and dolphins belonging to the Cetacean and duyung or dugong of the order Sirenia. These rare animals are protected by law. However, the frequency of marine mammal occurrences stranded in Indonesia is now getting higher, as in East Java. Based on data from whale stranding of Indonesia, at least 12 marine mammal stranded incident occurred only in East Java in 2003-2017. Some events are also reported by BKSDA East Java and BPSPL Denpasar. Knowledge and readiness of coastal communities is needed in the handling of fast and precise in accordance with the guidelines handling. Fast and proper handling of alive stranded animals can reduce the risk of death so that the animals' hope for life and can be restored to their habitats is higher. Whereas in dead stranded animals, rapid and good handling can reduce the risk of disease from stranded animal carcasses.

scholarly journals Global nutrient cycling by commercially-targeted marine fish

2021 ◽  
Author(s):  
Priscilla Le Mézo ◽  
Jérôme Guiet ◽  
Kim Scherrer ◽  
Daniele Bianchi ◽  
Eric Galbraith
Keyword(s):  
Nutrient Cycling ◽  
Marine Fish ◽  
Essential Elements ◽  
Global Ocean ◽  
Nutrient Concentrations ◽  
Size Spectrum ◽  
Mesopelagic Fish ◽  
Fish Biomass ◽  
Fishing Activity

Abstract. Throughout the course of their lives fish ingest food containing essential elements, including nitrogen (N), phosphorus (P) and iron (Fe). Some of these elements are retained in the fish body to build new biomass, which acts as a stored reservoir of nutrients, while the rest is excreted or egested, providing a recycling flux to water. Fishing activity has modified the fish biomass distribution worldwide and consequently may have altered fish-mediated nutrient cycling, but this possibility remains largely unassessed, mainly due to the difficulty of estimating global fish biomass and metabolic rates. Here we quantify the role of commercially-targeted marine fish between 10 g and 100 kg () in the cycling of N, P and Fe in the global ocean, and its change due to fishing activity, by using a global size-spectrum model of marine fish populations calibrated to observations of fish catches. Our results show that the amount of nutrients stored in the global pristine , biomass was generally small compared to the ambient surface nutrient concentrations but significant in the nutrient-poor regions of the world: the North Atlantic for P, the oligotrophic gyres for N and the High Nutrient Low Chlorophyll (HNLC) regions for Fe. Similarly, the rate of nutrient removed from the ocean through fishing is globally small compared to the inputs, but can be important locally especially for Fe in the equatorial Pacific and along the western margin of South America and Africa. This model allowed us to compute the spatial distribution of the cycling of elements by the biomass at pristine and global peak catch state, which is relatively small compared to the estimated primary production demand for nutrients and estimated export production of nutrients. Pristine cycling (excretion + egestion) accounted for less than 2.7 % of the primary productivity demand for N, P and Fe globally. Relative to the export of nutrients, modeled global pristine egestion represents on average 2.3 %, 3.0 % and 1.1–22 % for N, P and Fe (low-high estimates), respectively, with a higher fraction in the low-export oligotrophic tropical gyres. Our study highlights the role of the fraction of the icthyosphere (i.e. does not include non-commercial species such as mesopelagic fish) on nutrient storage and cycling, and the potential role of fishing activities on this cycling, which could be of importance in regions of low nutrient concentration, high fish biomass and/or high productivity demand, and especially at the more local scale for Fe.

Encounters with wild, ecotour and captive marine mammals: what do they tell us about human wellbeing and environmental behaviour?

2020 ◽  
Author(s):  
Rachel Yerbury ◽  
William Boyd ◽  
Betty Weiler
Keyword(s):  
Marine Mammal ◽  
Marine Mammals ◽  
Human Life ◽  
Connection To Nature ◽  
Environmental Behaviour ◽  
Health And Wellbeing ◽  
Human Wellbeing ◽  
In The Wild ◽  
Nature Contact

Nature recreation can be beneficial for human health and wellbeing, and this paperinvites discussion about whether environmental behaviour nature contact can influence naturecontact. As human life becomes more urbanised, people interact less closely with nature,which weakens and nature connections are weakened. Tourism provides an opportunity toenhance nature contact, and hence nature connection, and may, motivate pro-environmentalbehaviour. This study uses the ‘R’ statistical package to analyse questionnaire data from 679participants who have encountered marine mammals in the wild, as part of an ecotour, and incaptive settings. It considers the question: Does a connection to nature mediate the rolebetween nature contact and wellbeing, and do marine mammal experiences specificallycontribute to human wellbeing and environmental behaviour? The role of nature connectionas a mediator between nature contact and wellbeing is described in a structural equationmodel. Marine mammal experiences are shown to be significantly and positively related tohuman wellbeing (three-way ANOVA) and environmental behaviour (Kruskal-Wallis HTest). We conclude that nature connectedness mediates the effect of nature contact onwellbeing, and marine mammal experiences have an effect on wellbeing and environmentalbehaviour. This study adds to research on cetacean experiences by including all marinemammals across different experience types. The results assist identify paths through whichrecreation time may achieve a two-way benefit of wellbeing and environmental behaviour.

Role of trophic models and indicators in current marine fisheries management

2015 ◽  
Vol 538 ◽  
pp. 257-272 ◽  
Author(s):  
C Longo ◽  
S Hornborg ◽  
V Bartolino ◽  
MT Tomczak ◽  
L Ciannelli ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Marine Fisheries ◽  
Trophic Models

Recommendations for Sustainable Cetacean-Based Tourism in French Territories: A Review on the Industry and Current Management Actions

2020 ◽  
Vol 15 (3) ◽  
pp. 211-235
Author(s):  
Josephine Chazot ◽  
Ludovic Hoarau ◽  
Pamela Carzon ◽  
Jeanne Wagner ◽  
Stéphanie Sorby ◽  
...  
Keyword(s):  
Marine Mammal ◽  
Marine Mammals ◽  
French Polynesia ◽  
Legal Framework ◽  
Whale Watching ◽  
Cetacean Species ◽  
Commercial Activities ◽  
Management Actions ◽  
Overseas Territories ◽  
Socioeconomic Benefits

Whale-watching activities provide important socioeconomic benefits for local communities and constitute powerful platform incentives for marine mammals' protection or more broadly marine environments. However, these activities can cause adverse effects on targeted populations, with considerable downside associated risks of injuries and fatality for whale watchers during inwater interactions. France with its overseas territories has the second largest exclusive economic zone (EEZ), in which more than half of existing cetacean species are encountered. In these territories, recreational and commercial whale watching, including swim-with cetacean activities, have recently developed. Yet few studies focused on these activities and their associated impacts across French territories, leading to an unclear assessment of the situation. To address this issue, we reviewed cetaceans' occurrence within the French EEZ, whale-watching industry, targeted species, local management of marine mammal-based tourism activities, and regulations in France mainland and some overseas territories (Reunion Island, Mayotte, and French Polynesia). Fortyeight species are encountered in the French EEZ, and 15 are targeted by whale-watching activities. A total of 185 operators, including 34% offering swim-with-cetaceans tours, offered trips in France and overseas in 2019. While several more or less restrictive regulations exist locally, our results indicate that French's national legal framework for marine mammals' protection remains inadequate and insufficient to cope with the recent development of this activity. As conservation biologists, managers, and stakeholders from these French territories, we cooperated to provide general guidelines for a sustainable development of whale watching at a national scale. We urge (1) to legally acknowledge and regulate whale-watching commercial activities; (2) to create a national legal framework regarding whale watching and swim-with marine mammals practices, while accounting for local distinctiveness and disparities across regions; (3) to conduct more research to evaluate local short- and long-term impacts on targeted marine mammal populations as well as the socioeconomic benefits; and (4) to reinforce synergetic relations between the different stakeholders.

scholarly journals The isotopic niche of Atlantic, biting marine mammals and its relationship to skull morphology and body size

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Massimiliano Drago ◽  
Marco Signaroli ◽  
Meica Valdivia ◽  
Enrique M. González ◽  
Asunción Borrell ◽  
...  
Keyword(s):  
Body Size ◽  
Atlantic Ocean ◽  
Fisheries Management ◽  
Marine Mammals ◽  
Trophic Position ◽  
Sympatric Species ◽  
Isotopic Niche ◽  
Apex Predators ◽  
Skull Morphology ◽  
Ecosystem Based Fisheries Management

AbstractUnderstanding the trophic niches of marine apex predators is necessary to understand interactions between species and to achieve sustainable, ecosystem-based fisheries management. Here, we review the stable carbon and nitrogen isotope ratios for biting marine mammals inhabiting the Atlantic Ocean to test the hypothesis that the relative position of each species within the isospace is rather invariant and that common and predictable patterns of resource partitioning exists because of constrains imposed by body size and skull morphology. Furthermore, we analyze in detail two species-rich communities to test the hypotheses that marine mammals are gape limited and that trophic position increases with gape size. The isotopic niches of species were highly consistent across regions and the topology of the community within the isospace was well conserved across the Atlantic Ocean. Furthermore, pinnipeds exhibited a much lower diversity of isotopic niches than odontocetes. Results also revealed body size as a poor predictor of the isotopic niche, a modest role of skull morphology in determining it, no evidence of gape limitation and little overlap in the isotopic niche of sympatric species. The overall evidence suggests limited trophic flexibility for most species and low ecological redundancy, which should be considered for ecosystem-based fisheries management.

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