scholarly journals Ecological Trap or Favorable Habitat? First Evidence That Immature Sea Turtles May Survive at Their Range-Limits in the North-East Atlantic

2021 ◽  
Vol 8 ◽  
Author(s):  
Philippine Chambault ◽  
Philippe Gaspar ◽  
Florence Dell’Amico

Unusual environmental events can push marine animals outside their physiological tolerances through changes in trophic and/or thermal conditions. Such events typically increase the risk of stranding. Rescue Centers offer a unique opportunity to report animals in distress and satellite track rehabilitated individuals to identify potential new habitats and support an effective conservation of these endangered species. By combining sightings (1988–2020) and tracking data (2008–2020) collected along the French Atlantic and English Channel coasts, our study assessed if the Bay of Biscay is an ecological trap or a favorable habitat for immature sea turtles. The largest tracked individuals migrated westward to pelagic waters, likely toward their natal beaches, while smaller individuals remained within the Bay of Biscay (BoB) and crossed colder (mean: 17.8 ± 3.0°C) but more productive waters. The turtles’ directions differed from the ones of ocean currents, excluding a passive advection to these unexpected habitats. Although the BoB might be thermally unsuitable in winter, the higher micronekton biomass predicted in this region could offer a productive foraging habitat for immature turtles. However, the majority of the sightings referred to individuals stranded alive (75%), suggesting this area could also act as an ecological trap for the smallest individuals that are mostly reported in winter suffering cold-stunning. Assumed to be outside the species range, our results reveal a potential foraging ground in the North-East Atlantic for these young turtles, confirming the crucial role of the rehabilitation centers and the need to continue prioritizing conservation of these endangered species, particularly vulnerable at this stage and at such temperate latitudes.

Author(s):  
Florencio Aguirrezabalaga ◽  
Argiloa Ceberio ◽  
Dieter Fiege

Octomagelona bizkaiensis (Annelida: Polychaeta), a new genus and species of the family Magelonidae is described from the north-eastern Atlantic. The specimens were collected from the Capbreton Canyon, Bay of Biscay, at a depth of 1000–1040 m. The new genus and species differs from all known genera and species of the family Magelonidae by the presence of eight instead of nine thoracic chaetigers.


2019 ◽  
Author(s):  
James R Robbins ◽  
Lucy Babey ◽  
Clare B Embling

Background. Citizen science is increasingly popular and has the potential to collect extensive datasets at lower costs than traditional surveys. Ferries have been used to collect data on cetacean populations for decades, providing long-term time series allowing for monitoring of cetacean populations. One cetacean species of concern is the common dolphin, which have been found stranded around the north-east Atlantic in recent years, with high numbers on French coasts being attributed to fisheries bycatch. We estimate common dolphin densities in north-east Atlantic and investigate the power of citizen science data to identify changes in marine mammal densities and areas of importance. Materials & Methods. Data were collected by citizen scientists on ferries between April and October in 2006 - 2017. Common dolphin sightings data from two ferry routes in the Bay of Biscay (n= 569), Celtic Sea (n= 260), and English Channel (n= 75) were used to estimate detection probabilities with detection functions. Density Surface Models estimated density across ferry routes, accounting for the influence of environmental (chlorophyll a, sea surface temperature, depth, and slope), spatial (latitude and longitude) and temporal terms (year and Julian day). Results. Overall detection probability was highest in the English Channel (0.384) and Bay of Biscay (0.348), and lowest in the Celtic Sea (0.158). Common dolphins were estimated to occur in higher densities in the Celtic Sea (0.400 per km) and the Bay of Biscay (0.319 per km), with low densities in the English Channel (0.025 per km). Densities in the Celtic Sea have been relatively stable on the ferry route since 2006 with a slight decrease in 2017. Densities peaked in the Bay of Biscay in 2013 with lower numbers since. The general trend in the English Channel is for increasing densities of common dolphins over time since 2009. Discussion. This study highlights the effectiveness of citizen science data to investigate the distribution and density of cetaceans. The densities and temporal changes shown by this study are representative of those from wider-ranging robust estimates. We highlight the ability of citizen science to collect data over extensive periods of time which complements traditional surveys. Such long-term data are important to identify changes within a population; however, citizen science data may, in some situations, present challenges. We provide recommendations to ensure high-quality data which can be used to inform management and conservation of cetacean populations.


Author(s):  
L. W Byrne

Only one species met with on this cruise appears to have been previously undescribed.Although all the other species were already known from similar localities in the North-east Atlantic, attention may be called to an interesting series of the young of Synaphobranchus pinnatus and to the capture of numerous young examples of Onus biscayensis.When compared with the results of the hauls taken by H.M.S. Research, a little farther south and over very much deeper soundings, the list of species taken by the Huxley is chiefly remarkable for the entire absence of Stomias boa, Gonostoma microdon, and G. bathyphilum, the range of none of which seems to extend into waters as shallow as those fished by the Huxley.


Author(s):  
Caroline R. Weir ◽  
Jonathan Stokes ◽  
Clive Martin ◽  
Pablo Cermeño

Three sightings of Mesoplodon beaked whales are reported from the Bay of Biscay, north-east Atlantic. All sightings comprised one or two animals, breaching repeatedly in proximity to the survey vessel, and occurred at between 2200 and 4100 m water depth. Descriptive and photographic data are compared with published accounts of Mesoplodon species in the north-east Atlantic, and the identification of the animals as True's beaked whale (Mesoplodon mirus) concurs with all observed features. Within the north-east Atlantic, True's beaked whale is the only Mesoplodon species that could produce the single, closely-spaced parallel-paired scar observed on one animal. Our observations are consistent with the first live sightings of True's beaked whale in the Bay of Biscay, and only the second documented record worldwide.


Author(s):  
James R Robbins ◽  
Lucy Babey ◽  
Clare B Embling

Background. Citizen science is increasingly popular and has the potential to collect extensive datasets at lower costs than traditional surveys. Ferries have been used to collect data on cetacean populations for decades, providing long-term time series allowing for monitoring of cetacean populations. One cetacean species of concern is the common dolphin, which have been found stranded around the north-east Atlantic in recent years, with high numbers on French coasts being attributed to fisheries bycatch. We estimate common dolphin densities in north-east Atlantic and investigate the power of citizen science data to identify changes in marine mammal densities and areas of importance. Materials & Methods. Data were collected by citizen scientists on ferries between April and October in 2006 - 2017. Common dolphin sightings data from two ferry routes in the Bay of Biscay (n= 569), Celtic Sea (n= 260), and English Channel (n= 75) were used to estimate detection probabilities with detection functions. Density Surface Models estimated density across ferry routes, accounting for the influence of environmental (chlorophyll a, sea surface temperature, depth, and slope), spatial (latitude and longitude) and temporal terms (year and Julian day). Results. Overall detection probability was highest in the English Channel (0.384) and Bay of Biscay (0.348), and lowest in the Celtic Sea (0.158). Common dolphins were estimated to occur in higher densities in the Celtic Sea (0.400 per km) and the Bay of Biscay (0.319 per km), with low densities in the English Channel (0.025 per km). Densities in the Celtic Sea have been relatively stable on the ferry route since 2006 with a slight decrease in 2017. Densities peaked in the Bay of Biscay in 2013 with lower numbers since. The general trend in the English Channel is for increasing densities of common dolphins over time since 2009. Discussion. This study highlights the effectiveness of citizen science data to investigate the distribution and density of cetaceans. The densities and temporal changes shown by this study are representative of those from wider-ranging robust estimates. We highlight the ability of citizen science to collect data over extensive periods of time which complements traditional surveys. Such long-term data are important to identify changes within a population; however, citizen science data may, in some situations, present challenges. We provide recommendations to ensure high-quality data which can be used to inform management and conservation of cetacean populations.


Author(s):  
Jérôme Jourde ◽  
Leandro Sampaio ◽  
Ruth Barnich ◽  
Paulo Bonifácio ◽  
Céline Labrune ◽  
...  

Malmgrenia louiseae sp. nov. is described from both the western Mediterranean in the Gulf of Lions, and the north-east Atlantic from off Portugal and the Bay of Biscay. The species was found in muddy sediments in shallow water and is possibly associated with echiurids or synaptid holothurians. Malmgrenia louiseae sp. nov. can be clearly distinguished from all other known Malmgrenia species by the presence of an infra-acicular process in addition to the supra-acicular process on the acicular lobe of the neuropodia, the lack of microtubercules on the elytra, two kinds of notochaetae (stout with blunt tip and slender with fine pointed tip), and exclusively unidentate neurochaetae. An identification key to the north-east Atlantic and Mediterranean Malmgrenia species is provided.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7809
Author(s):  
James R. Robbins ◽  
Travis Park ◽  
Ellen J. Coombs

Mesoplodont beaked whales are one of the most enigmatic mammalian genera. We document a pod of four beaked whales in the Bay of Biscay breaching and tail slapping alongside a large passenger ferry. Photographs of the animals were independently reviewed by experts, and identified as True’s beaked whales (Mesoplodon mirus). This is the first conclusive live sighting of these animals in the north-east Atlantic, and adds information to previous sightings that are likely to have been M. mirus. Photographs of an adult male appears to show two supernumerary teeth posterior to the apical mandibular tusks. Whilst analysed museum specimens (n = 8) did not show evidence of alveoli in this location, there is evidence of vestigial teeth and variable dentition in many beaked whale species. This is the first such record of supernumerary teeth in True’s beaked whales.


Zootaxa ◽  
2019 ◽  
Vol 4700 (4) ◽  
pp. 431-444
Author(s):  
TINA N. MOLODTSOVA ◽  
ÁLVARO ALTUNA ◽  
JASON M. HALL-SPENCER

A new species of antipatharian (black coral) in the genus Trissopathes is described. It is common in the bathyal zone of the north-east Atlantic, including the Bay of Biscay, Celtic Slope and adjacent banks and seamounts. The species is often observed in underwater photographs from untrawled parts of carbonate mounds in the area. Trissopathes grasshoffi sp. nov. can be easily distinguished from its three congeners by having relatively sparse branching, a higher density of primary pinnules, and 3–6 secondary anterolateral pinnules as well as by the shape and size of its spines. The present state of knowledge of Trissopathes is reviewed. 


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