Recent changes in distribution and relative abundance of cetaceans in the Norwegian Sea and their relationship with potential prey

Nøttestad, Leif; Krafft, Bjørn A.; Anthonypillai, Valentine; Bernasconi, Matteo; Langård, Lise; Mørk, Herdis Langøy; Fernö, Anders

doi:10.3389/fevo.2014.00083

Cited by 35 publications

(41 citation statements)

References 31 publications

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“…Of those factors that it was not possible to include in the analysis, prey availability is one that inevitably influences distribution and abundance of marine mammals (e.g. Nottestad et al 2015), and al though there is a paucity of research on the direct and indirect impact of construction-related activity on fish species, there is No. of vessels per scan Table 1.…”

Section: Discussionmentioning

confidence: 99%

“…This is further complicated by variation in spatial and temporal trends in occurrence attributable to stochasticity within the marine environment (e.g. Nottestad et al 2015). In some cases, such as harbour maintenance and development, the activities undertaken can be discrete and cover relatively small geographical regions (Pirotta et al 2013); however, for large-scale projects, it is possible for developments to have multiple vessels, often conducting different activities in close proximity to one another.…”

Section: Introductionmentioning

confidence: 99%

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Effect of construction-related activities and vessel traffic on marine mammals

Culloch¹,

Anderwald²,

Brandecker³

et al. 2016

Mar. Ecol. Prog. Ser.

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During the construction of a gas pipeline from an offshore gas field in northwest Ireland, a year-round shore-based marine mammal monitoring programme was undertaken. Using 6 yr of data, generalised estimating equations-generalised additive models (GEE-GAMs) were used to investigate if construction-related activity and vessel traffic influenced the occurrence of common dolphin, minke whale, harbour porpoise and grey seal within the area where the pipeline made landfall. Construction-related activity reduced harbour porpoise and minke whale presence, whilst an increase in vessel numbers (independent of construction-related activity) reduced common dolphin presence. All species showed some degree of annual and seasonal variation in occurrence. For common dolphins and harbour porpoises, we found similar seasonal patterns to those reported in broader Irish waters, which tentatively suggests that seasonal patterns persisted irrespective of construction-related activity or vessel traffic, indicating that any impact might have been only short-term. Multiple construction-related activities occurred simultaneously in different areas, and the inter-annual variation may, in part, be an indication of variation in species' response to particular activities, their intensity and their location. However, the precise location of the activities was not regularly recorded, limiting our ability to investigate the fine-scale spatio−temporal impact of the diverse range of construction-related activities. Improved communication and coordination between developers, regulators and scientists will help ensure that monitoring programmes are effective and efficient, to better inform our understanding of potential impacts and to mitigate effectively against them for future developments.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of construction-related activities and vessel traffic on marine mammals

Culloch¹,

Anderwald²,

Brandecker³

et al. 2016

Mar. Ecol. Prog. Ser.

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show abstract

“…Changes in the availability of prey can cause cetaceans to change their distribution (e.g. Nøttestad et al 2015). Nevertheless 30 of 103 | Wageningen Marine Research report C097/17 Ruzicka et al (2013) point out that the actual food conflict between man and cetaceans is relatively limited and would remain so even if cetacean populations were to increase 5 fold.…”

Section: Overfishing (Indirect Effects)mentioning

confidence: 99%

Priorities in management implementation for marine mammal conservation in the Saba sector of the Yarari sanctuary

Debrot¹,

Tamis²,

Haan³

et al. 2017

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A. O. Debrot, J.E.Tamis, D. de Haan, M. Scheidat, J.T. van der Wal, 2017 was formally established on September 2, 2015. It is currently composed of two sectors: one surrounding Saba and the Saba Bank and one covering the EEZ waters of Bonaire. In order to help establish an effective cetacean conservation management plan for the Saba and Saba Bank sector of the sanctuary we here review the main marine mammal threats, help identify main management goals and make both governance and management recommendations based both on stakeholder interviews and a management review of functioning marine mammal sanctuaries in the WesternAtlantic.There are 8 species of marine mammals known to occur in the windward Dutch Caribbean YarariSanctuary. The sanctuary has relatively low levels of human activity. Based on our review, cumulative contaminant impacts -such as oil contamination originating from St. Eustatius -are potentially highest, followed by collision impacts due to the relatively high level of shipping traffic. Other factors such as, fishery entanglement, bycatch-impacts and marine debris impacts are likely low compared to many areas directly outside the sanctuary. While whale & dolphin watching impacts are still probably negligible, the impacts of anthropogenic noise, climate-change impacts and cumulative impacts still remain unknown but are potentially high.Five main clusters of interrelated goals and objectives were identified based on expert and management stakeholder interviews. The most essential proximate goal for management should be to establish a minimum structural level of institutional capacity. Under the reigning conditions of resource limitation, the next key goal should be to establish effective collaboration towards jointly achieving the higher management goals and objectives.Based on our review of species, threats, operations of other sanctuaries and expert and stakeholder input we list 23 priority recommendations and action points towards implementation of cetacean conservation for the Saba and Saba Bank Yarari sector. Governance• Use the Saba Bank Management Unit (SMBU) governance model for Yarari management implementation.• Consider merging Yarari tasks into the SMBU to effectuate resource pooling and prevent management fragmentation. Legal resources• Design and implement a simple legal mandate for Yarari management.• Copy and implement international legal guidelines for whale watching.• Revise the Fishery Framework Act BES (Vissery Visserijwet besluit BES) or draft a Decree (Regeling) under the Nature Conservation Framework Act BES (Wet Grondslagen Natuurbeheer en-bescherming, WGN) to forbid all forms of pelagic (not benthic) longline and purse seine fishing in Yarari waters.• Devise and implement legal measures and guidelines to safeguard Yarari from anthropogenic noise pollution. Finances• Based on the review of functioning sanctuaries, and current stressor levels, a basic annual budget of US$ 150 K will be sufficient to implement satisfactory marine mammal conservation.• Focus expenditures on mana...

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“…Both are large pelagic stocks with complex dynamics as a result of extensive migration patterns in combination with ecological and environmental drivers, notably the abundance and distribution of their prey (Prokopchuk and Sentyabov, 2006;Vikebø et al, 2012;Skagseth et al, 2015), predators (Saetre et al, 2002;Durant et al, 2014;Nøttestad et al, 2015), and competitors (Cabral and Murta, 2002;Langøy et al, 2012) as well as climatic and oceanic conditions (H at un et al, 2009a, b;Payne et al, 2012). These dynamics lead to fluctuations in stock size that are typically hard to predict and add to the uncertainty in estimates and predictions.…”

Section: Introductionmentioning

confidence: 99%

Can less be more? Effects of reduced frequency of surveys and stock assessments

Zimmermann

Enberg

2016

ICES Journal of Marine Science

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Uncertain and inaccurate estimates are a prevailing problem in stock assessment, despite increasingly sophisticated estimation methods and substantial usage of scientific and financial resources. Annual scientific surveys and assessment group meetings require frequent use of research vessels and skilled research staff and are, therefore, particularly costly. This data-and work-intensive approach is often considered paramount for reliable stock estimates and risk management. However, it remains an open question whether the benefits of increasing assessment effort outweigh its marginal costs, or whether the potential impacts of investing less in assessments could generate net benefits. In this study, we explore how different scenarios of reduced survey and assessment frequencies affect estimated stock biomass, predicted catch, and uncertainty. Data of two Northeast Atlantic stocks, blue whiting (Micromesistius poutassou) and Norwegian spring-spawning herring (Clupea harengus), and a widely applied stock assessment model are used to compare the impacts of removing surveys and/or annual assessments. The results show that lower survey and/or assessment frequencies tend to result in deviating estimates of spawning-stock biomass and catch and larger confidence intervals, the observed differences being, however, mostly small. While scenarios without a survey datapoint in the assessment year generally produced the largest deviations in estimates, biannual surveys in general did not affect assessment performance substantially. This indicates that a reduced frequency of surveys and assessments could be an acceptable measure to reduce assessment costs and increase the efficiency of fisheries management, particularly when accompanied by thorough management strategy evaluations and risk assessments.

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Recent changes in distribution and relative abundance of cetaceans in the Norwegian Sea and their relationship with potential prey

Cited by 35 publications

References 31 publications

Effect of construction-related activities and vessel traffic on marine mammals

Effect of construction-related activities and vessel traffic on marine mammals

Priorities in management implementation for marine mammal conservation in the Saba sector of the Yarari sanctuary

Can less be more? Effects of reduced frequency of surveys and stock assessments

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