Predicting future distributions of lanternfish, a significant ecological resource within the Southern Ocean

Freer, Jennifer; Tarling, Geraint A.; Collins, Martin A.; Partridge, Julian C.; Genner, Martin J.

doi:10.1111/ddi.12934

Cited by 49 publications

(63 citation statements)

References 88 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Understanding mesopelagic distribution has also been the focus of recent attempts to classify the global biogeography of the mesopelagic zone (Proud et al 2017, Sayre et al 2017, Sutton et al 2017, Rey-gondeau et al 2018. These global studies, and recent work predicting future distributions of lan ternfish at high latitudes (Freer et al 2019), have focused on temperature, salinity, primary production, and surface wind stress as environmental drivers, but have not included light despite a long history of compelling observational studies (i.a. Kampa 1971, Dickson 1972, Tont 1976, Aksnes et al 2017.…”

Section: Discussionmentioning

confidence: 99%

Light comfort zone in a mesopelagic fish emerges from adaptive behaviour along a latitudinal gradient

Langbehn¹,

Aksnes²,

Kaartvedt³

et al. 2019

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Throughout the oceans, small fish and other micronekton migrate between daytime depths of several hundred meters and near-surface waters at night. These diel vertical migrations of mesopelagic organisms structure pelagic ecosystems through trophic interactions, and are a key element in the biological carbon pump. However, depth distributions and migration amplitude vary greatly. Suggested proximate causes of the migration such as oxygen, temperature, and light often correlate and therefore the causal underpinnings have remained unclear. Using mesopelagic fishes and the Norwegian Sea as a study system, we developed a dynamic state variable model that finds optimal migration patterns that we validate with acoustic observations along a latitudinal gradient. The model describes predation risk and bioenergetics, and maximizes expected energy surplus, a proxy for Darwinian fitness. The model allows us to disentangle the drivers of migration and make predictions about depth distribution and related fitness consequences along a latitudinal trajectory with strong gradients in environmental drivers and vertical distribution of scattering layers. We show that the model-predicted vertical migration of mesopelagic fishes matches that observed along this transect. For most situations, modelled mesopelagic fish behaviour can be well described by a light comfort zone near identical to that derived from observations. By selectively keeping light or temperature constant, the model reveals that temperature, in comparison with light, has little effect on depth distribution. We find that water clarity, which limits how deeply light can penetrate into the ocean, structures daytime depths, while surface light at night controlled the depth of nocturnal ascents.

show abstract

Section: Discussionmentioning

confidence: 99%

Light comfort zone in a mesopelagic fish emerges from adaptive behaviour along a latitudinal gradient

Langbehn¹,

Aksnes²,

Kaartvedt³

et al. 2019

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…Myctophids are also likely to be impacted directly by sustained ocean-warming in the Scotia Sea, with changes in temperature altering their distribution patterns, abundance, life cycles and behavior, which could further affect food web stability in the region (Freer et al, 2019). For example, a recent study found that the Scotia Sea myctophid community adheres to Bergmann's rule, a size-temperature rule whereby species and individuals are larger in colder waters at higher latitudes (Saunders and Tarling, 2018).…”

Section: Impact Of Ocean-warming On Food Web Dynamicsmentioning

confidence: 99%

Myctophid Fish (Family Myctophidae) Are Central Consumers in the Food Web of the Scotia Sea (Southern Ocean)

et al. 2019

Self Cite

View full text Add to dashboard Cite

Myctophids are the most abundant and diverse mesopelagic fishes in the Southern Ocean. They are a conduit of energy between primary consumers and higher marine predators, and between the surface layers and the mesopelagic depths. However, there remain major uncertainties about their ecology, particularly regarding their role in Southern Ocean food webs in waters south of the Antarctic Polar Front, which are often regarded as dominated by Antarctic krill. Limited data on the feeding ecology of myctophids has made it difficult to assess the importance of myctophids as consumers of krill and how they fit in the traditional view of a krill-dominated system (diatom-krillhigher predator). We provide a new assessment of the role of myctophids in Southern Ocean food webs using information from recent trophodynamic studies of myctophids conducted in the Scotia Sea, one of the most productive regions of the Southern Ocean and a region that sustains both major populations of higher predators (sea birds, seals, whales) and important commercial fisheries (krill, toothfish, and mackerel icefish). Collectively, these data show that myctophids have a central role in Southern Ocean food webs as both predators and prey. Large myctophid species are prevalent consumers of krill throughout their distributional range and in different seasons in the Scotia Sea. Moreover, best estimates of both myctophid and higher predator consumption of krill to date indicate that large myctophids are the greatest predators of krill in this region, consuming almost as much krill as do all other vertebrates. Nevertheless, there are several smaller myctophid species that do not eat krill, instead consuming copepods and other small euphausiids. Myctophids therefore link primary producers to higher predators through both krill-dependent and krill-independent trophic pathways, emphasizing their importance in regional food webs. Consequently, trophic pathways involving large myctophids are unlikely to be exempt from the direct consequences of projected redistribution and/or reduction in krill population biomass under scenarios of ocean-warming, whilst trophic pathways involving small myctophids may be more resilient to such effects and become increasingly important to higher trophic levels. Further studies are required to determine the extent to which myctophids can maintain food web stability and sustain higher predator populations Frontiers in Marine Science | www.frontiersin.org 1 September 2019 | Volume 6 | Article 530 Saunders et al. Trophodynamics of Scotia Sea Myctophidsduring periods of prolonged reductions in krill abundance. Including knowledge of the role of myctophids in Southern Ocean food webs will be important for developing robust projections of the impacts of future change to inform decision making for conservation and management.

show abstract

“…This makes them highly vulnerable to climate change (Peron et al, 2012;Bost et al, 2013Bost et al, , 2015Cristofari et al, 2018). Shifts in their main prey, myctophids, are predicted under future climate change scenarios, with unknown consequences for king penguins (Freer et al, 2019).…”

Section: Ecological Outcomesmentioning

confidence: 99%

Managing Marine Protected Areas in Remote Areas: The Case of the Subantarctic Heard and McDonald Islands

2019

View full text Add to dashboard Cite

Large marine protected areas (MPAs) are increasingly being established to contribute to global conservation targets but present an immense challenge for managers as they seek to govern human interactions with the environment over a vast geographical expanse. These challenges are further compounded by the remote location of some MPAs, which magnify the costs of management activities. However, large size and remoteness alone may be insufficient to achieve conservation outcomes in the absence of critical management functions such as environmental monitoring and enforcement. The Australian subantarctic Heard Island and McDonald Islands (HIMI) Marine Reserve is among the world's most remote MPAs with notoriously harsh oceanographic conditions, and yet the region's rich mammal and fish resources have been exploited intermittently since the mid-1800s. More recently, the development of lucrative international markets for Patagonian toothfish, sold as Chilean seabass, led to the growth in both legal and illegal fishing. In 2002, to conserve the unique ecology and biodiversity in the area, Australia declared a 65,000 km2 MPA around HIMI. Worldwide, government agencies have, however, struggled to develop cost-effective institutional arrangements for conservation. This paper therefore draws upon the social-ecological systems metaanalysis database (SESMAD) to characterize the structure of conservation governance and outcomes in the HIMI Marine Reserve. The Marine Reserve has generally been successful in supporting a sustainable fishery while addressing threats to biodiversity. The remote and isolated nature of the Marine Reserve was critical to its success, but also benefited greatly from collaborations between managers and the fishing industry. Commercial fishers keep watch over the Reserve while fishing, report any observations of illegal fishing (none since 2006/07), and have at times been asked to verify remote observation of potential illegal fishing vessels. The industry also undertakes annual ecological surveys in the MPA, allowing managers to track environmental trends. The fishing industry itself highlights the importance of industry participation in conservation

show abstract

Predicting future distributions of lanternfish, a significant ecological resource within the Southern Ocean

Cited by 49 publications

References 88 publications

Light comfort zone in a mesopelagic fish emerges from adaptive behaviour along a latitudinal gradient

Light comfort zone in a mesopelagic fish emerges from adaptive behaviour along a latitudinal gradient

Myctophid Fish (Family Myctophidae) Are Central Consumers in the Food Web of the Scotia Sea (Southern Ocean)

Managing Marine Protected Areas in Remote Areas: The Case of the Subantarctic Heard and McDonald Islands

Contact Info

Product

Resources

About