Investigation into the Presence of Symbiodiniaceae in Antipatharians (Black Corals)

Here, we report a new broad approach to investigating the presence and density of Symbiodiniaceae cells in corals of the order Antipatharia subclass Hexacorallia, commonly known as black corals. Antipatharians are understudied ecosystem engineers of shallow (<30 m depth), mesophotic (30–150 m) and deep-sea (>200 m) reefs. They provide habitat to numerous organisms, enhancing and supporting coral reef biodiversity globally. Nonetheless, little biological and ecological information exists on antipatharians, including the extent to which global change disturbances are threatening their health. The previous assumption that they were exempted from threats related to the phenomenon known as bleaching was challenged by the recent findings of high densities of dinoflagellates within three antipatharian colonies. Further studies were thus necessary to investigate the broader uniformity of these findings. Here we report results of an integrated methodology combining microscopy and molecular techniques to investigate the presence and estimate the density of Symbiodiniaceae cells within two antipatharians species—Cupressopathes abies and Stichopathes maldivensis—from both shallow and mesophotic reefs of SW Madagascar. We found that Symbiodiniaceae-like cells were present within samples of both species collected from both shallow and mesophotic reefs, although the overall cell density was very low (0–4 cell mm−3). These findings suggest that presence or high abundance of Symbiodiniaceae is not characteristic of all antipatharians, which is relevant considering the bleaching phenomenon affecting other corals. However, the possibility of higher densities of dinoflagellates in other antipatharians or in colonies exposed to higher light irradiance deserves further investigation.

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Investigating densities of Symbiodiniaceae in two species of Antipatharians (black corals) from Madagascar

10.1101/2021.01.22.427691 ◽

2021 ◽

Author(s):

Erika Gress ◽

Igor Eeckhaut ◽

Mathilde Godefroid ◽

Philippe Dubois ◽

Jonathan Richir ◽

...

Keyword(s):

Climate Change ◽

Global Change ◽

Deep Sea ◽

Methodological Approach ◽

Integrated Design ◽

Molecular Techniques ◽

Marine Fauna ◽

Vast Number ◽

Ecological Information ◽

Black Corals

AbstractHere, we report the first methodological approach to investigate the presence and estimate the density of Symbiodiniaceae cells in corals of the order Antipatharia subclass Hexacorallia, known as black corals. Antipatharians are understudied ecosystem engineers of shallow (<30 m depth), mesophotic (30-150 m) and deep-sea (>200 m) reefs. They provide habitat to a vast number of marine fauna, enhancing and supporting coral reefs biodiversity globally. Nonetheless, little biological and ecological information exists on antipatharians, including the extent at which global change disturbances are threatening these corals. The assumption that they were exempted from threats related to climate change was challenged by findings of high density of dinoflagellates within three antipatharian colonies. Further methodical studies were necessary to investigate the regularity of these findings. An integrated design combining microscopy and molecular techniques was used to investigate the presence and estimate density of Symbiodiniaceae cells within two antipatharians species -Cupressopathes abies and Stichopathes maldivensis -from shallow and mesophotic reefs of SW Madagascar. Symbiodiniaceae-like cells were found within the two species from both shallow and mesophotic reefs, although the overall cell density was very low (0-4 cell mm-3). These findings suggest that high abundance of Symbiodiniaceae is not characteristic of antipatharians, which has relevant implications considering disruptions associated to climate change affecting other corals. However, the high densities of dinoflagellates found in antipatharian colonies exposed to higher light irradiance in other studies should be further examined.

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New Scientific Information Can Help to Inform the Evaluation of EU Deep-sea Fisheries Regulations

The International Journal of Marine and Coastal Law ◽

10.1163/15718085-bja10074 ◽

2021 ◽

pp. 1-20

Author(s):

Phillip J Turner ◽

Matthew Gianni ◽

Ellen Kenchington ◽

Sebastian Valanko ◽

David E Johnson

Keyword(s):

Deep Sea ◽

Scientific Information ◽

Fish Population ◽

Molecular Techniques ◽

Fish Stocks ◽

Horizon 2020 ◽

Management Measures ◽

Sea Fish ◽

The Eu ◽

Fish Population Structure

Abstract The European Union’s deep-sea fisheries regulations (Regulation (EU) No. 2016/2336) established obligations to manage deep-sea fisheries and to protect vulnerable marine ecosystems (VMEs). The European Commission is scheduled to complete a review of the regulations in 2021, providing an opportunity for new scientific information to be incorporated into the implementation of the regulations. Here, we summarise research outputs from the EU-funded Horizon 2020 ATLAS Project and explain their relevance to the regulation of deep-sea fisheries in EU waters. ATLAS research has increased our understanding of the distribution of VMEs and their importance in terms of ecosystem functioning. ATLAS research has also highlighted the utility of molecular techniques to understand fish population structure and the potential for habitat suitability models to help incorporate climate change into decision-making. Building on these scientific advances, we provide recommendations to help increase the effectiveness of management measures to conserve deep-sea fish stocks and protect VMEs.

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Perspectives for an integrated understanding of tropical and temperate high-mountain lakes

Journal of Limnology ◽

10.4081/jlimnol.2016.1372 ◽

2016 ◽

Vol 75 (s1) ◽

Cited By ~ 21

Author(s):

Jordi Catalan ◽

John C. Donato Rondón

Keyword(s):

Global Change ◽

Freshwater Ecosystems ◽

Mountain Lakes ◽

Molecular Techniques ◽

Mountain Lake ◽

Tropical Lakes ◽

High Mountain ◽

Essential Difference ◽

High Mountain Lakes ◽

High Mountain Lake

<p>High mountain lakes are extreme freshwater ecosystems and excellent sentinels of current global change. They are likely among the most comparable ecosystems across the world. The largest contrast occurs between lakes in temperate and tropical areas. The main difference arises from the seasonal patterns of heat exchange and the external loadings (carbon, phosphorus, metals). The consequence is a water column structure based on temperature, in temperate lakes, and oxygen, in tropical lakes. This essential difference implies that, in tropical lakes, one can expect a more sustained productivity throughout the year; a higher nutrient internal loading based on the mineralization of external organic matter; higher nitrification-denitrification potential related to the oxyclines; and a higher metal mobilization due to the permanently reduced bottom layer. Quantifying and linking these and other biogeochemical pathways to particular groups of organisms is in the current agenda of high-mountain limnology. The intrinsic difficulties of the taxonomic study of many of the organisms inhabiting these systems can be now overcome with the use of molecular techniques. These techniques will not only provide a much less ambiguous taxonomic knowledge of the microscopic world, but also will unveil new biogeochemical pathways that are difficult to measure chemically and will solve biogeographical puzzles of the distribution of some macroscopic organism, tracing the relationship with other areas. Daily variability and vertical gradients in the tropics are the main factors of phytoplankton species turnover in tropical lakes; whereas seasonality is the main driver in temperate communities. The study of phytoplankton in high-mountain lakes only makes sense in an integrated view of the microscopic ecosystem. A large part of the plankton biomass is in heterotrophic, and mixotrophic organisms and prokaryotes compete for dissolved resources with eukaryotic autotrophs. In fact, high-mountain lake systems are excellent model ecosystems for applying an investigation linking airshed to sediments functional views. Additionally, the study of the mountain lakes districts as functional metacommunity units may reveal key differences in the distribution of organisms of limited (slow) dispersal. We propose that limnological studies at tropical and temperate high mountain lakes should adhere to a common general paradigm. In which biogeochemical processes are framed by the airshed-to-sediment continuum concept and the biogeographical processes in the functional lake district concept. The solid understanding of the fundamental limnological processes will facilitate stronger contributions to the assessment of the impacts of the on-going global change in remote areas.</p>

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Critical Information Gaps Impeding Understanding of the Role of Larval Connectivity Among Coral Reef Islands in an Era of Global Change

Frontiers in Marine Science ◽

10.3389/fmars.2018.00290 ◽

2018 ◽

Vol 5 ◽

Cited By ~ 4

Author(s):

Peter J. Edmunds ◽

Shelby E. McIlroy ◽

Mehdi Adjeroud ◽

Put Ang ◽

Jessica L. Bergman ◽

...

Keyword(s):

Coral Reef ◽

Global Change ◽

Critical Information ◽

Larval Connectivity ◽

Reef Islands ◽

Information Gaps

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Mesophotic Ecosystems: The Link between Shallow and Deep-Sea Habitats

Diversity ◽

10.3390/d12110411 ◽

2020 ◽

Vol 12 (11) ◽

pp. 411

Author(s):

Gal Eyal ◽

Hudson T. Pinheiro

Keyword(s):

Coral Reef ◽

Deep Sea ◽

New Technologies ◽

Mesophotic Coral Ecosystems ◽

Tropical Regions ◽

Biogeographic Patterns ◽

Global Diversity ◽

Coral Reef Ecosystems ◽

Threatened Habitats ◽

Management And Conservation

Mesophotic ecosystems (MEs) are characterized by the presence of light-dependent organisms, found at depths ranging from ~30 to 150 m in temperate, subtropical and tropical regions. These communities occasionally create massive reef structures with diverse but characteristic morphologies, which serve as the framework builders of those ecosystems. In many localities, MEs are physically linked with shallow and deep-sea habitats, and while taxa from both environments share this space, a unique and endemic biodiversity is also found. The main MEs studied to date are the mesophotic coral ecosystems (MCEs) and the temperate mesophotic ecosystems (TMEs), which have received increased attention during the last decade. As shallow coral reef ecosystems are among the most threatened habitats on Earth, the potential of MEs to act as refugia and contribute to the resilience of the whole ecosystem has been a subject of scrutiny. New technologies and methods have become more available to study these deeper parts of the reef ecosystems, yielding many new discoveries. However, basic gaps in knowledge remain in our scientific understanding of the global diversity of MEs, limiting our ability to recognize biogeographic patterns and to make educated decisions for the management and conservation of these ecosystems.

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