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Map showing the locations of Grand Bank, Flemish Cap (FC) and Flemish Pass (FP) in the northwest Altantic. The Canadian exclusive economic zone (EEZ) is indicated by a dashed line separating the Nose and the Tail from the rest of Grand Bank. Selected depth contours are illustrated (m) and the postions of the depth-strati fi ed random trawl locations used to sample the benthos are indicated by solid black circles. NAFO statistical divisions 3LMNO are indicated. Bathymetric curves were obtained from the Canadian Hydrographic Service.
Source publication
The structure, composition and distribution of epibenthic invertebrate assemblages on the Tail of the Grand Bank of Newfoundland and Flemish Cap (northwest Atlantic) were sampled using depth-stratified trawls. Faunal analysis of 152 uniquely identified taxa produced hierarchical synoptic tables of species associations with diagnostic indicators bas...
Contexts in source publication
Context 1
... benthic faunas. Since Nesis' study, several geo- graphically restricted studies have been done on the continental shelf of the Grand Banks (Hutcheson et al., 1981; Schneider et al., 1987; Gilkinson, 2013) and on the slope (Houston and Haedrich, 1984; Barrio Froján et al., 2012) mostly restricted to macrofauna; while other studies have been undertaken on speci fi c megafaunal groups such as sponges (Murillo et al., 2012; Beazley et al., 2013; Beazley et al., 2015), corals (e.g. Wareham and Edinger, 2007; Murillo et al., 2011; Baker et al., 2012), hydroids (Altuna et al., 2013), mollusks (Allen, 1965), and echinoderms (Haedrich and Maunder, 1985; Gale et al., 2014). The objective of this study was to describe the structure, composition and distribution of epibenthic invertebrate megafaunal assemblages in the international waters on the Tail of the Grand Bank and on Flemish Cap as sampled with research trawls, and to identify the key factors that shape their spatial distribution. Environmental processes acting at multiple spatial scales control benthic community structure (Williams et al., 2010). We examined the role of regional variables: depth, substrate type, water temperature and salinity, and location in shaping species composition using ordination and regression techniques. We predicted signi fi cant changes in epibenthic megafaunal assemblages with depth, given that the principal factors shaping the faunal composition of the bathyal benthos are generally correlated with depth (e.g. Carney, 2005; Rex et al., 2006). Speci fi cally, we examined whether epibenthic megafaunal assemblages in the study area followed predicted global patterns for faunal distributions along continental margins, that is, faunal boundaries or transition zones occurring at 300 – 500 m and 1000 m (Carney, 2005). Further, the Labrador Current creates a semi-permanent anticyclonic gyre around Flemish Cap which promotes retention (Colbourne and Foote, 2000), while the deep Flemish Pass presents a bathymetric barrier between Flemish Cap and Grand Bank ( Fig. 1). By including the Tail of Grand Bank in our analyses we were able to evaluate the uniqueness of the Flemish Cap fauna relative to the fauna of the continental shelf. Fishing intensity is an important anthropogenic factor de- termining the magnitude and direction of long-term changes in benthic communities (Pitcher et al., 2000). However, long-term impacts of trawling on benthic communities at the scale over which fi sheries operate are challenging to assess, particularly due to the dif fi culty in controlling for natural variations in the ecosystem (Hall, 1999; Kenchington et al., 2007). Due to selective removal of large and fragile species, heavily fi shed areas may be- come dominated by smaller, more resilient species (e.g., Kenchington et al., 2007) and by scavenging and predatory species (e.g., Ramsay et al., 1998). We quanti fi ed the relationship between re- cent (2001 – 2009) fi shing intensity and epibenthic assemblage structure and predicted that areas of high fi shing intensity will have fewer large fragile epifaunal species and a lower diversity compared to lightly fi shed areas at similar depths. Lastly, to the extent possible considering the different sampling devices employed, we compared our results with those of Nesis (1965) to determine whether the epibenthic assemblages in this region have been altered over the past 50 years through the dramatic events noted above, which have in fl uenced other ecosystem components. The study area lies in the international waters of the northwest Atlantic (Fig. 1). The Grand Bank is the largest and easternmost of the offshore banks from Labrador to New England, USA on the Canadian continental shelf, and extends outside of the Canadian Exclusive Economic Zone (EEZ) of 200 nautical miles into international waters (Fig. 1). Water depth over most of the bank is generally less than 100 m. However, towards the southeast the bank shoals and depth decreases to less than 50 m. The southern Grand Bank, outside of the Canadian EEZ is known as the Tail of the Grand Bank, and the continental slope in this area steeply plunges to depths greater than 3000 m. Eastward of Grand Bank, is the Flemish Cap, another fi sh-rich plateau lying entirely in international waters (Fig. 1). Flemish Cap is somewhat circular in shape with a radius of approximately 200 km at the 500 m isobath. The shallowest depth is 126 m and occurs in the southeastern quadrant. Flemish Cap is separated from the Grand Bank by a large perched basin, Flemish Pass, which descends to approximately 1200 m depth. This topography results in a complex hydrography owing to the occurrence of two water masses: the cold Labrador Current Slope water, fl owing from the north, and the warm Gulf Stream water, fl owing from the south (Colbourne and Foote, 2000). Around the Tail of the Grand Bank the Labrador Current and the Gulf Stream meet giving rise to the North Atlantic Current (NAC) and the NAC front (Gil et al., 2004). Data used in this study came from two separate bottom trawl research surveys targeting ground fi sh: (1) the Spanish 3NO survey, carried out by the Instituto Español de Oceanografía (IEO), which sampled the Tail of the Grand Bank (NAFO Divs. 3NO) between 45 and 1374 m depth (Fig. 1); and (2) the EU Flemish Cap survey, carried out by the IEO together with the Instituto de In- vestigaciones Marinas (IIM) and the Instituto Português do Mar e da Atmosfera (IPMA), which sampled all of the trawlable area of Flemish Cap (NAFO Div. 3M) between 138 and 1488 m depth. Both surveys were conducted on the Spanish research vessel (RV) “ Vizconde de Eza ” between May and July 2007. Trawl stations were allocated using a depth-strati fi ed random sampling design and conducted with standardized 30-min bottom trawls and a vessel speed of approximately 3 knots. This design is optimized for the collection of the target species. A Campelen 1800 bottom trawl gear with some modi fi cations and a mean swept area of 67,000 m 2 was used on the Grand Bank. This gear has a 20 mm cod-end mesh size. A Lofoten bottom trawl gear was used on the Flemish Cap with a 35 mm cod-end mesh size and mean swept area of 39,000 m 2 . For comparative purposes the results were expressed as biomass per area swept by the gear (kg 10,000 m À 2 ), although we caution that catchability of benthic species within and between gears cannot be corrected. A total of 110 bottom trawls from the Tail of the Grand Bank and 176 for the Flemish Cap were processed (Fig. 1). All epibenthic invertebrate fauna retained by the net were sorted on board to the lowest possible taxonomic level. Wet weight for each taxon was determined, and numbers of individuals recorded (except for colonial organisms that were only weighed). Vouchers specimens for subsequent de fi nitive identi fi cation in the laboratory were pre- served in 70% alcohol or 4% buffered formaldehyde depending on the taxon. Oceanographic data were recorded with a SBE 25 Sealogger CTD provided with depth, temperature and conductivity sensors. The CTD was dropped at a speed of 1 m s À 1 and con fi gured to acquire two samples per second on the downward drop. CTD stations were planned for the end of each bottom trawl set. Due to time constraints and CTD problems, not all bottom trawl sets where associated with CTD data. A total of 66 valid CTD ...
Context 2
... benthic faunas. Since Nesis' study, several geo- graphically restricted studies have been done on the continental shelf of the Grand Banks (Hutcheson et al., 1981; Schneider et al., 1987; Gilkinson, 2013) and on the slope (Houston and Haedrich, 1984; Barrio Froján et al., 2012) mostly restricted to macrofauna; while other studies have been undertaken on speci fi c megafaunal groups such as sponges (Murillo et al., 2012; Beazley et al., 2013; Beazley et al., 2015), corals (e.g. Wareham and Edinger, 2007; Murillo et al., 2011; Baker et al., 2012), hydroids (Altuna et al., 2013), mollusks (Allen, 1965), and echinoderms (Haedrich and Maunder, 1985; Gale et al., 2014). The objective of this study was to describe the structure, composition and distribution of epibenthic invertebrate megafaunal assemblages in the international waters on the Tail of the Grand Bank and on Flemish Cap as sampled with research trawls, and to identify the key factors that shape their spatial distribution. Environmental processes acting at multiple spatial scales control benthic community structure (Williams et al., 2010). We examined the role of regional variables: depth, substrate type, water temperature and salinity, and location in shaping species composition using ordination and regression techniques. We predicted signi fi cant changes in epibenthic megafaunal assemblages with depth, given that the principal factors shaping the faunal composition of the bathyal benthos are generally correlated with depth (e.g. Carney, 2005; Rex et al., 2006). Speci fi cally, we examined whether epibenthic megafaunal assemblages in the study area followed predicted global patterns for faunal distributions along continental margins, that is, faunal boundaries or transition zones occurring at 300 – 500 m and 1000 m (Carney, 2005). Further, the Labrador Current creates a semi-permanent anticyclonic gyre around Flemish Cap which promotes retention (Colbourne and Foote, 2000), while the deep Flemish Pass presents a bathymetric barrier between Flemish Cap and Grand Bank ( Fig. 1). By including the Tail of Grand Bank in our analyses we were able to evaluate the uniqueness of the Flemish Cap fauna relative to the fauna of the continental shelf. Fishing intensity is an important anthropogenic factor de- termining the magnitude and direction of long-term changes in benthic communities (Pitcher et al., 2000). However, long-term impacts of trawling on benthic communities at the scale over which fi sheries operate are challenging to assess, particularly due to the dif fi culty in controlling for natural variations in the ecosystem (Hall, 1999; Kenchington et al., 2007). Due to selective removal of large and fragile species, heavily fi shed areas may be- come dominated by smaller, more resilient species (e.g., Kenchington et al., 2007) and by scavenging and predatory species (e.g., Ramsay et al., 1998). We quanti fi ed the relationship between re- cent (2001 – 2009) fi shing intensity and epibenthic assemblage structure and predicted that areas of high fi shing intensity will have fewer large fragile epifaunal species and a lower diversity compared to lightly fi shed areas at similar depths. Lastly, to the extent possible considering the different sampling devices employed, we compared our results with those of Nesis (1965) to determine whether the epibenthic assemblages in this region have been altered over the past 50 years through the dramatic events noted above, which have in fl uenced other ecosystem components. The study area lies in the international waters of the northwest Atlantic (Fig. 1). The Grand Bank is the largest and easternmost of the offshore banks from Labrador to New England, USA on the Canadian continental shelf, and extends outside of the Canadian Exclusive Economic Zone (EEZ) of 200 nautical miles into international waters (Fig. 1). Water depth over most of the bank is generally less than 100 m. However, towards the southeast the bank shoals and depth decreases to less than 50 m. The southern Grand Bank, outside of the Canadian EEZ is known as the Tail of the Grand Bank, and the continental slope in this area steeply plunges to depths greater than 3000 m. Eastward of Grand Bank, is the Flemish Cap, another fi sh-rich plateau lying entirely in international waters (Fig. 1). Flemish Cap is somewhat circular in shape with a radius of approximately 200 km at the 500 m isobath. The shallowest depth is 126 m and occurs in the southeastern quadrant. Flemish Cap is separated from the Grand Bank by a large perched basin, Flemish Pass, which descends to approximately 1200 m depth. This topography results in a complex hydrography owing to the occurrence of two water masses: the cold Labrador Current Slope water, fl owing from the north, and the warm Gulf Stream water, fl owing from the south (Colbourne and Foote, 2000). Around the Tail of the Grand Bank the Labrador Current and the Gulf Stream meet giving rise to the North Atlantic Current (NAC) and the NAC front (Gil et al., 2004). Data used in this study came from two separate bottom trawl research surveys targeting ground fi sh: (1) the Spanish 3NO survey, carried out by the Instituto Español de Oceanografía (IEO), which sampled the Tail of the Grand Bank (NAFO Divs. 3NO) between 45 and 1374 m depth (Fig. 1); and (2) the EU Flemish Cap survey, carried out by the IEO together with the Instituto de In- vestigaciones Marinas (IIM) and the Instituto Português do Mar e da Atmosfera (IPMA), which sampled all of the trawlable area of Flemish Cap (NAFO Div. 3M) between 138 and 1488 m depth. Both surveys were conducted on the Spanish research vessel (RV) “ Vizconde de Eza ” between May and July 2007. Trawl stations were allocated using a depth-strati fi ed random sampling design and conducted with standardized 30-min bottom trawls and a vessel speed of approximately 3 knots. This design is optimized for the collection of the target species. A Campelen 1800 bottom trawl gear with some modi fi cations and a mean swept area of 67,000 m 2 was used on the Grand Bank. This gear has a 20 mm cod-end mesh size. A Lofoten bottom trawl gear was used on the Flemish Cap with a 35 mm cod-end mesh size and mean swept area of 39,000 m 2 . For comparative purposes the results were expressed as biomass per area swept by the gear (kg 10,000 m À 2 ), although we caution that catchability of benthic species within and between gears cannot be corrected. A total of 110 bottom trawls from the Tail of the Grand Bank and 176 for the Flemish Cap were processed (Fig. 1). All epibenthic invertebrate fauna retained by the net were sorted on board to the lowest possible taxonomic level. Wet weight for each taxon was determined, and numbers of individuals recorded (except for colonial organisms that were only weighed). Vouchers specimens for subsequent de fi nitive identi fi cation in the laboratory were pre- served in 70% alcohol or 4% buffered formaldehyde depending on the taxon. Oceanographic data were recorded with a SBE 25 Sealogger CTD provided with depth, temperature and conductivity sensors. The CTD was dropped at a speed of 1 m s À 1 and con fi gured to acquire two samples per second on the downward drop. CTD stations were planned for the end of each bottom trawl set. Due to time constraints and CTD problems, not all bottom trawl sets where associated with CTD data. A total of 66 valid CTD ...
Context 3
... benthic faunas. Since Nesis' study, several geo- graphically restricted studies have been done on the continental shelf of the Grand Banks (Hutcheson et al., 1981; Schneider et al., 1987; Gilkinson, 2013) and on the slope (Houston and Haedrich, 1984; Barrio Froján et al., 2012) mostly restricted to macrofauna; while other studies have been undertaken on speci fi c megafaunal groups such as sponges (Murillo et al., 2012; Beazley et al., 2013; Beazley et al., 2015), corals (e.g. Wareham and Edinger, 2007; Murillo et al., 2011; Baker et al., 2012), hydroids (Altuna et al., 2013), mollusks (Allen, 1965), and echinoderms (Haedrich and Maunder, 1985; Gale et al., 2014). The objective of this study was to describe the structure, composition and distribution of epibenthic invertebrate megafaunal assemblages in the international waters on the Tail of the Grand Bank and on Flemish Cap as sampled with research trawls, and to identify the key factors that shape their spatial distribution. Environmental processes acting at multiple spatial scales control benthic community structure (Williams et al., 2010). We examined the role of regional variables: depth, substrate type, water temperature and salinity, and location in shaping species composition using ordination and regression techniques. We predicted signi fi cant changes in epibenthic megafaunal assemblages with depth, given that the principal factors shaping the faunal composition of the bathyal benthos are generally correlated with depth (e.g. Carney, 2005; Rex et al., 2006). Speci fi cally, we examined whether epibenthic megafaunal assemblages in the study area followed predicted global patterns for faunal distributions along continental margins, that is, faunal boundaries or transition zones occurring at 300 – 500 m and 1000 m (Carney, 2005). Further, the Labrador Current creates a semi-permanent anticyclonic gyre around Flemish Cap which promotes retention (Colbourne and Foote, 2000), while the deep Flemish Pass presents a bathymetric barrier between Flemish Cap and Grand Bank ( Fig. 1). By including the Tail of Grand Bank in our analyses we were able to evaluate the uniqueness of the Flemish Cap fauna relative to the fauna of the continental shelf. Fishing intensity is an important anthropogenic factor de- termining the magnitude and direction of long-term changes in benthic communities (Pitcher et al., 2000). However, long-term impacts of trawling on benthic communities at the scale over which fi sheries operate are challenging to assess, particularly due to the dif fi culty in controlling for natural variations in the ecosystem (Hall, 1999; Kenchington et al., 2007). Due to selective removal of large and fragile species, heavily fi shed areas may be- come dominated by smaller, more resilient species (e.g., Kenchington et al., 2007) and by scavenging and predatory species (e.g., Ramsay et al., 1998). We quanti fi ed the relationship between re- cent (2001 – 2009) fi shing intensity and epibenthic assemblage structure and predicted that areas of high fi shing intensity will have fewer large fragile epifaunal species and a lower diversity compared to lightly fi shed areas at similar depths. Lastly, to the extent possible considering the different sampling devices employed, we compared our results with those of Nesis (1965) to determine whether the epibenthic assemblages in this region have been altered over the past 50 years through the dramatic events noted above, which have in fl uenced other ecosystem components. The study area lies in the international waters of the northwest Atlantic (Fig. 1). The Grand Bank is the largest and easternmost of the offshore banks from Labrador to New England, USA on the Canadian continental shelf, and extends outside of the Canadian Exclusive Economic Zone (EEZ) of 200 nautical miles into international waters (Fig. 1). Water depth over most of the bank is generally less than 100 m. However, towards the southeast the bank shoals and depth decreases to less than 50 m. The southern Grand Bank, outside of the Canadian EEZ is known as the Tail of the Grand Bank, and the continental slope in this area steeply plunges to depths greater than 3000 m. Eastward of Grand Bank, is the Flemish Cap, another fi sh-rich plateau lying entirely in international waters (Fig. 1). Flemish Cap is somewhat circular in shape with a radius of approximately 200 km at the 500 m isobath. The shallowest depth is 126 m and occurs in the southeastern quadrant. Flemish Cap is separated from the Grand Bank by a large perched basin, Flemish Pass, which descends to approximately 1200 m depth. This topography results in a complex hydrography owing to the occurrence of two water masses: the cold Labrador Current Slope water, fl owing from the north, and the warm Gulf Stream water, fl owing from the south (Colbourne and Foote, 2000). Around the Tail of the Grand Bank the Labrador Current and the Gulf Stream meet giving rise to the North Atlantic Current (NAC) and the NAC front (Gil et al., 2004). Data used in this study came from two separate bottom trawl research surveys targeting ground fi sh: (1) the Spanish 3NO survey, carried out by the Instituto Español de Oceanografía (IEO), which sampled the Tail of the Grand Bank (NAFO Divs. 3NO) between 45 and 1374 m depth (Fig. 1); and (2) the EU Flemish Cap survey, carried out by the IEO together with the Instituto de In- vestigaciones Marinas (IIM) and the Instituto Português do Mar e da Atmosfera (IPMA), which sampled all of the trawlable area of Flemish Cap (NAFO Div. 3M) between 138 and 1488 m depth. Both surveys were conducted on the Spanish research vessel (RV) “ Vizconde de Eza ” between May and July 2007. Trawl stations were allocated using a depth-strati fi ed random sampling design and conducted with standardized 30-min bottom trawls and a vessel speed of approximately 3 knots. This design is optimized for the collection of the target species. A Campelen 1800 bottom trawl gear with some modi fi cations and a mean swept area of 67,000 m 2 was used on the Grand Bank. This gear has a 20 mm cod-end mesh size. A Lofoten bottom trawl gear was used on the Flemish Cap with a 35 mm cod-end mesh size and mean swept area of 39,000 m 2 . For comparative purposes the results were expressed as biomass per area swept by the gear (kg 10,000 m À 2 ), although we caution that catchability of benthic species within and between gears cannot be corrected. A total of 110 bottom trawls from the Tail of the Grand Bank and 176 for the Flemish Cap were processed (Fig. 1). All epibenthic invertebrate fauna retained by the net were sorted on board to the lowest possible taxonomic level. Wet weight for each taxon was determined, and numbers of individuals recorded (except for colonial organisms that were only weighed). Vouchers specimens for subsequent de fi nitive identi fi cation in the laboratory were pre- served in 70% alcohol or 4% buffered formaldehyde depending on the taxon. Oceanographic data were recorded with a SBE 25 Sealogger CTD provided with depth, temperature and conductivity sensors. The CTD was dropped at a speed of 1 m s À 1 and con fi gured to acquire two samples per second on the downward drop. CTD stations were planned for the end of each bottom trawl set. Due to time constraints and CTD problems, not all bottom trawl sets where associated with CTD data. A total of 66 valid CTD ...
Context 4
... benthic faunas. Since Nesis' study, several geo- graphically restricted studies have been done on the continental shelf of the Grand Banks (Hutcheson et al., 1981; Schneider et al., 1987; Gilkinson, 2013) and on the slope (Houston and Haedrich, 1984; Barrio Froján et al., 2012) mostly restricted to macrofauna; while other studies have been undertaken on speci fi c megafaunal groups such as sponges (Murillo et al., 2012; Beazley et al., 2013; Beazley et al., 2015), corals (e.g. Wareham and Edinger, 2007; Murillo et al., 2011; Baker et al., 2012), hydroids (Altuna et al., 2013), mollusks (Allen, 1965), and echinoderms (Haedrich and Maunder, 1985; Gale et al., 2014). The objective of this study was to describe the structure, composition and distribution of epibenthic invertebrate megafaunal assemblages in the international waters on the Tail of the Grand Bank and on Flemish Cap as sampled with research trawls, and to identify the key factors that shape their spatial distribution. Environmental processes acting at multiple spatial scales control benthic community structure (Williams et al., 2010). We examined the role of regional variables: depth, substrate type, water temperature and salinity, and location in shaping species composition using ordination and regression techniques. We predicted signi fi cant changes in epibenthic megafaunal assemblages with depth, given that the principal factors shaping the faunal composition of the bathyal benthos are generally correlated with depth (e.g. Carney, 2005; Rex et al., 2006). Speci fi cally, we examined whether epibenthic megafaunal assemblages in the study area followed predicted global patterns for faunal distributions along continental margins, that is, faunal boundaries or transition zones occurring at 300 – 500 m and 1000 m (Carney, 2005). Further, the Labrador Current creates a semi-permanent anticyclonic gyre around Flemish Cap which promotes retention (Colbourne and Foote, 2000), while the deep Flemish Pass presents a bathymetric barrier between Flemish Cap and Grand Bank ( Fig. 1). By including the Tail of Grand Bank in our analyses we were able to evaluate the uniqueness of the Flemish Cap fauna relative to the fauna of the continental shelf. Fishing intensity is an important anthropogenic factor de- termining the magnitude and direction of long-term changes in benthic communities (Pitcher et al., 2000). However, long-term impacts of trawling on benthic communities at the scale over which fi sheries operate are challenging to assess, particularly due to the dif fi culty in controlling for natural variations in the ecosystem (Hall, 1999; Kenchington et al., 2007). Due to selective removal of large and fragile species, heavily fi shed areas may be- come dominated by smaller, more resilient species (e.g., Kenchington et al., 2007) and by scavenging and predatory species (e.g., Ramsay et al., 1998). We quanti fi ed the relationship between re- cent (2001 – 2009) fi shing intensity and epibenthic assemblage structure and predicted that areas of high fi shing intensity will have fewer large fragile epifaunal species and a lower diversity compared to lightly fi shed areas at similar depths. Lastly, to the extent possible considering the different sampling devices employed, we compared our results with those of Nesis (1965) to determine whether the epibenthic assemblages in this region have been altered over the past 50 years through the dramatic events noted above, which have in fl uenced other ecosystem components. The study area lies in the international waters of the northwest Atlantic (Fig. 1). The Grand Bank is the largest and easternmost of the offshore banks from Labrador to New England, USA on the Canadian continental shelf, and extends outside of the Canadian Exclusive Economic Zone (EEZ) of 200 nautical miles into international waters (Fig. 1). Water depth over most of the bank is generally less than 100 m. However, towards the southeast the bank shoals and depth decreases to less than 50 m. The southern Grand Bank, outside of the Canadian EEZ is known as the Tail of the Grand Bank, and the continental slope in this area steeply plunges to depths greater than 3000 m. Eastward of Grand Bank, is the Flemish Cap, another fi sh-rich plateau lying entirely in international waters (Fig. 1). Flemish Cap is somewhat circular in shape with a radius of approximately 200 km at the 500 m isobath. The shallowest depth is 126 m and occurs in the southeastern quadrant. Flemish Cap is separated from the Grand Bank by a large perched basin, Flemish Pass, which descends to approximately 1200 m depth. This topography results in a complex hydrography owing to the occurrence of two water masses: the cold Labrador Current Slope water, fl owing from the north, and the warm Gulf Stream water, fl owing from the south (Colbourne and Foote, 2000). Around the Tail of the Grand Bank the Labrador Current and the Gulf Stream meet giving rise to the North Atlantic Current (NAC) and the NAC front (Gil et al., 2004). Data used in this study came from two separate bottom trawl research surveys targeting ground fi sh: (1) the Spanish 3NO survey, carried out by the Instituto Español de Oceanografía (IEO), which sampled the Tail of the Grand Bank (NAFO Divs. 3NO) between 45 and 1374 m depth (Fig. 1); and (2) the EU Flemish Cap survey, carried out by the IEO together with the Instituto de In- vestigaciones Marinas (IIM) and the Instituto Português do Mar e da Atmosfera (IPMA), which sampled all of the trawlable area of Flemish Cap (NAFO Div. 3M) between 138 and 1488 m depth. Both surveys were conducted on the Spanish research vessel (RV) “ Vizconde de Eza ” between May and July 2007. Trawl stations were allocated using a depth-strati fi ed random sampling design and conducted with standardized 30-min bottom trawls and a vessel speed of approximately 3 knots. This design is optimized for the collection of the target species. A Campelen 1800 bottom trawl gear with some modi fi cations and a mean swept area of 67,000 m 2 was used on the Grand Bank. This gear has a 20 mm cod-end mesh size. A Lofoten bottom trawl gear was used on the Flemish Cap with a 35 mm cod-end mesh size and mean swept area of 39,000 m 2 . For comparative purposes the results were expressed as biomass per area swept by the gear (kg 10,000 m À 2 ), although we caution that catchability of benthic species within and between gears cannot be corrected. A total of 110 bottom trawls from the Tail of the Grand Bank and 176 for the Flemish Cap were processed (Fig. 1). All epibenthic invertebrate fauna retained by the net were sorted on board to the lowest possible taxonomic level. Wet weight for each taxon was determined, and numbers of individuals recorded (except for colonial organisms that were only weighed). Vouchers specimens for subsequent de fi nitive identi fi cation in the laboratory were pre- served in 70% alcohol or 4% buffered formaldehyde depending on the taxon. Oceanographic data were recorded with a SBE 25 Sealogger CTD provided with depth, temperature and conductivity sensors. The CTD was dropped at a speed of 1 m s À 1 and con fi gured to acquire two samples per second on the downward drop. CTD stations were planned for the end of each bottom trawl set. Due to time constraints and CTD problems, not all bottom trawl sets where associated with CTD data. A total of 66 valid CTD ...
Context 5
... benthic faunas. Since Nesis' study, several geo- graphically restricted studies have been done on the continental shelf of the Grand Banks (Hutcheson et al., 1981; Schneider et al., 1987; Gilkinson, 2013) and on the slope (Houston and Haedrich, 1984; Barrio Froján et al., 2012) mostly restricted to macrofauna; while other studies have been undertaken on speci fi c megafaunal groups such as sponges (Murillo et al., 2012; Beazley et al., 2013; Beazley et al., 2015), corals (e.g. Wareham and Edinger, 2007; Murillo et al., 2011; Baker et al., 2012), hydroids (Altuna et al., 2013), mollusks (Allen, 1965), and echinoderms (Haedrich and Maunder, 1985; Gale et al., 2014). The objective of this study was to describe the structure, composition and distribution of epibenthic invertebrate megafaunal assemblages in the international waters on the Tail of the Grand Bank and on Flemish Cap as sampled with research trawls, and to identify the key factors that shape their spatial distribution. Environmental processes acting at multiple spatial scales control benthic community structure (Williams et al., 2010). We examined the role of regional variables: depth, substrate type, water temperature and salinity, and location in shaping species composition using ordination and regression techniques. We predicted signi fi cant changes in epibenthic megafaunal assemblages with depth, given that the principal factors shaping the faunal composition of the bathyal benthos are generally correlated with depth (e.g. Carney, 2005; Rex et al., 2006). Speci fi cally, we examined whether epibenthic megafaunal assemblages in the study area followed predicted global patterns for faunal distributions along continental margins, that is, faunal boundaries or transition zones occurring at 300 – 500 m and 1000 m (Carney, 2005). Further, the Labrador Current creates a semi-permanent anticyclonic gyre around Flemish Cap which promotes retention (Colbourne and Foote, 2000), while the deep Flemish Pass presents a bathymetric barrier between Flemish Cap and Grand Bank ( Fig. 1). By including the Tail of Grand Bank in our analyses we were able to evaluate the uniqueness of the Flemish Cap fauna relative to the fauna of the continental shelf. Fishing intensity is an important anthropogenic factor de- termining the magnitude and direction of long-term changes in benthic communities (Pitcher et al., 2000). However, long-term impacts of trawling on benthic communities at the scale over which fi sheries operate are challenging to assess, particularly due to the dif fi culty in controlling for natural variations in the ecosystem (Hall, 1999; Kenchington et al., 2007). Due to selective removal of large and fragile species, heavily fi shed areas may be- come dominated by smaller, more resilient species (e.g., Kenchington et al., 2007) and by scavenging and predatory species (e.g., Ramsay et al., 1998). We quanti fi ed the relationship between re- cent (2001 – 2009) fi shing intensity and epibenthic assemblage structure and predicted that areas of high fi shing intensity will have fewer large fragile epifaunal species and a lower diversity compared to lightly fi shed areas at similar depths. Lastly, to the extent possible considering the different sampling devices employed, we compared our results with those of Nesis (1965) to determine whether the epibenthic assemblages in this region have been altered over the past 50 years through the dramatic events noted above, which have in fl uenced other ecosystem components. The study area lies in the international waters of the northwest Atlantic (Fig. 1). The Grand Bank is the largest and easternmost of the offshore banks from Labrador to New England, USA on the Canadian continental shelf, and extends outside of the Canadian Exclusive Economic Zone (EEZ) of 200 nautical miles into international waters (Fig. 1). Water depth over most of the bank is generally less than 100 m. However, towards the southeast the bank shoals and depth decreases to less than 50 m. The southern Grand Bank, outside of the Canadian EEZ is known as the Tail of the Grand Bank, and the continental slope in this area steeply plunges to depths greater than 3000 m. Eastward of Grand Bank, is the Flemish Cap, another fi sh-rich plateau lying entirely in international waters (Fig. 1). Flemish Cap is somewhat circular in shape with a radius of approximately 200 km at the 500 m isobath. The shallowest depth is 126 m and occurs in the southeastern quadrant. Flemish Cap is separated from the Grand Bank by a large perched basin, Flemish Pass, which descends to approximately 1200 m depth. This topography results in a complex hydrography owing to the occurrence of two water masses: the cold Labrador Current Slope water, fl owing from the north, and the warm Gulf Stream water, fl owing from the south (Colbourne and Foote, 2000). Around the Tail of the Grand Bank the Labrador Current and the Gulf Stream meet giving rise to the North Atlantic Current (NAC) and the NAC front (Gil et al., 2004). Data used in this study came from two separate bottom trawl research surveys targeting ground fi sh: (1) the Spanish 3NO survey, carried out by the Instituto Español de Oceanografía (IEO), which sampled the Tail of the Grand Bank (NAFO Divs. 3NO) between 45 and 1374 m depth (Fig. 1); and (2) the EU Flemish Cap survey, carried out by the IEO together with the Instituto de In- vestigaciones Marinas (IIM) and the Instituto Português do Mar e da Atmosfera (IPMA), which sampled all of the trawlable area of Flemish Cap (NAFO Div. 3M) between 138 and 1488 m depth. Both surveys were conducted on the Spanish research vessel (RV) “ Vizconde de Eza ” between May and July 2007. Trawl stations were allocated using a depth-strati fi ed random sampling design and conducted with standardized 30-min bottom trawls and a vessel speed of approximately 3 knots. This design is optimized for the collection of the target species. A Campelen 1800 bottom trawl gear with some modi fi cations and a mean swept area of 67,000 m 2 was used on the Grand Bank. This gear has a 20 mm cod-end mesh size. A Lofoten bottom trawl gear was used on the Flemish Cap with a 35 mm cod-end mesh size and mean swept area of 39,000 m 2 . For comparative purposes the results were expressed as biomass per area swept by the gear (kg 10,000 m À 2 ), although we caution that catchability of benthic species within and between gears cannot be corrected. A total of 110 bottom trawls from the Tail of the Grand Bank and 176 for the Flemish Cap were processed (Fig. 1). All epibenthic invertebrate fauna retained by the net were sorted on board to the lowest possible taxonomic level. Wet weight for each taxon was determined, and numbers of individuals recorded (except for colonial organisms that were only weighed). Vouchers specimens for subsequent de fi nitive identi fi cation in the laboratory were pre- served in 70% alcohol or 4% buffered formaldehyde depending on the taxon. Oceanographic data were recorded with a SBE 25 Sealogger CTD provided with depth, temperature and conductivity sensors. The CTD was dropped at a speed of 1 m s À 1 and con fi gured to acquire two samples per second on the downward drop. CTD stations were planned for the end of each bottom trawl set. Due to time constraints and CTD problems, not all bottom trawl sets where associated with CTD data. A total of 66 valid CTD ...
Context 6
... benthic faunas. Since Nesis' study, several geo- graphically restricted studies have been done on the continental shelf of the Grand Banks (Hutcheson et al., 1981; Schneider et al., 1987; Gilkinson, 2013) and on the slope (Houston and Haedrich, 1984; Barrio Froján et al., 2012) mostly restricted to macrofauna; while other studies have been undertaken on speci fi c megafaunal groups such as sponges (Murillo et al., 2012; Beazley et al., 2013; Beazley et al., 2015), corals (e.g. Wareham and Edinger, 2007; Murillo et al., 2011; Baker et al., 2012), hydroids (Altuna et al., 2013), mollusks (Allen, 1965), and echinoderms (Haedrich and Maunder, 1985; Gale et al., 2014). The objective of this study was to describe the structure, composition and distribution of epibenthic invertebrate megafaunal assemblages in the international waters on the Tail of the Grand Bank and on Flemish Cap as sampled with research trawls, and to identify the key factors that shape their spatial distribution. Environmental processes acting at multiple spatial scales control benthic community structure (Williams et al., 2010). We examined the role of regional variables: depth, substrate type, water temperature and salinity, and location in shaping species composition using ordination and regression techniques. We predicted signi fi cant changes in epibenthic megafaunal assemblages with depth, given that the principal factors shaping the faunal composition of the bathyal benthos are generally correlated with depth (e.g. Carney, 2005; Rex et al., 2006). Speci fi cally, we examined whether epibenthic megafaunal assemblages in the study area followed predicted global patterns for faunal distributions along continental margins, that is, faunal boundaries or transition zones occurring at 300 – 500 m and 1000 m (Carney, 2005). Further, the Labrador Current creates a semi-permanent anticyclonic gyre around Flemish Cap which promotes retention (Colbourne and Foote, 2000), while the deep Flemish Pass presents a bathymetric barrier between Flemish Cap and Grand Bank ( Fig. 1). By including the Tail of Grand Bank in our analyses we were able to evaluate the uniqueness of the Flemish Cap fauna relative to the fauna of the continental shelf. Fishing intensity is an important anthropogenic factor de- termining the magnitude and direction of long-term changes in benthic communities (Pitcher et al., 2000). However, long-term impacts of trawling on benthic communities at the scale over which fi sheries operate are challenging to assess, particularly due to the dif fi culty in controlling for natural variations in the ecosystem (Hall, 1999; Kenchington et al., 2007). Due to selective removal of large and fragile species, heavily fi shed areas may be- come dominated by smaller, more resilient species (e.g., Kenchington et al., 2007) and by scavenging and predatory species (e.g., Ramsay et al., 1998). We quanti fi ed the relationship between re- cent (2001 – 2009) fi shing intensity and epibenthic assemblage structure and predicted that areas of high fi shing intensity will have fewer large fragile epifaunal species and a lower diversity compared to lightly fi shed areas at similar depths. Lastly, to the extent possible considering the different sampling devices employed, we compared our results with those of Nesis (1965) to determine whether the epibenthic assemblages in this region have been altered over the past 50 years through the dramatic events noted above, which have in fl uenced other ecosystem components. The study area lies in the international waters of the northwest Atlantic (Fig. 1). The Grand Bank is the largest and easternmost of the offshore banks from Labrador to New England, USA on the Canadian continental shelf, and extends outside of the Canadian Exclusive Economic Zone (EEZ) of 200 nautical miles into international waters (Fig. 1). Water depth over most of the bank is generally less than 100 m. However, towards the southeast the bank shoals and depth decreases to less than 50 m. The southern Grand Bank, outside of the Canadian EEZ is known as the Tail of the Grand Bank, and the continental slope in this area steeply plunges to depths greater than 3000 m. Eastward of Grand Bank, is the Flemish Cap, another fi sh-rich plateau lying entirely in international waters (Fig. 1). Flemish Cap is somewhat circular in shape with a radius of approximately 200 km at the 500 m isobath. The shallowest depth is 126 m and occurs in the southeastern quadrant. Flemish Cap is separated from the Grand Bank by a large perched basin, Flemish Pass, which descends to approximately 1200 m depth. This topography results in a complex hydrography owing to the occurrence of two water masses: the cold Labrador Current Slope water, fl owing from the north, and the warm Gulf Stream water, fl owing from the south (Colbourne and Foote, 2000). Around the Tail of the Grand Bank the Labrador Current and the Gulf Stream meet giving rise to the North Atlantic Current (NAC) and the NAC front (Gil et al., 2004). Data used in this study came from two separate bottom trawl research surveys targeting ground fi sh: (1) the Spanish 3NO survey, carried out by the Instituto Español de Oceanografía (IEO), which sampled the Tail of the Grand Bank (NAFO Divs. 3NO) between 45 and 1374 m depth (Fig. 1); and (2) the EU Flemish Cap survey, carried out by the IEO together with the Instituto de In- vestigaciones Marinas (IIM) and the Instituto Português do Mar e da Atmosfera (IPMA), which sampled all of the trawlable area of Flemish Cap (NAFO Div. 3M) between 138 and 1488 m depth. Both surveys were conducted on the Spanish research vessel (RV) “ Vizconde de Eza ” between May and July 2007. Trawl stations were allocated using a depth-strati fi ed random sampling design and conducted with standardized 30-min bottom trawls and a vessel speed of approximately 3 knots. This design is optimized for the collection of the target species. A Campelen 1800 bottom trawl gear with some modi fi cations and a mean swept area of 67,000 m 2 was used on the Grand Bank. This gear has a 20 mm cod-end mesh size. A Lofoten bottom trawl gear was used on the Flemish Cap with a 35 mm cod-end mesh size and mean swept area of 39,000 m 2 . For comparative purposes the results were expressed as biomass per area swept by the gear (kg 10,000 m À 2 ), although we caution that catchability of benthic species within and between gears cannot be corrected. A total of 110 bottom trawls from the Tail of the Grand Bank and 176 for the Flemish Cap were processed (Fig. 1). All epibenthic invertebrate fauna retained by the net were sorted on board to the lowest possible taxonomic level. Wet weight for each taxon was determined, and numbers of individuals recorded (except for colonial organisms that were only weighed). Vouchers specimens for subsequent de fi nitive identi fi cation in the laboratory were pre- served in 70% alcohol or 4% buffered formaldehyde depending on the taxon. Oceanographic data were recorded with a SBE 25 Sealogger CTD provided with depth, temperature and conductivity sensors. The CTD was dropped at a speed of 1 m s À 1 and con fi gured to acquire two samples per second on the downward drop. CTD stations were planned for the end of each bottom trawl set. Due to time constraints and CTD problems, not all bottom trawl sets where associated with CTD data. A total of 66 valid CTD ...
Citations
... Tests with equally sized P. ochraceus and E. troschelii did not display inter-and intraspecific interference behaviours [11], aligning with our results. This lack of agonistic behaviour may also be explained because H. lisa feeds primarily upon sponges [17,35], which are large, sessile, and abundant in deep waters off the coast of Newfoundland [42,43]; therefore, intraspecific competition for this resource may be reduced. ...
Competitive interactions come in a variety of forms and may be modulated by the size and number of individuals involved, and/or the resources available. Here, intra-and interspecific competitive behaviours for food (i.e., foraging/food search and feeding/food ingestion) were experimentally characterized and quantified in four co-existing deep-sea benthic species. Three sea stars (Ceramaster granularis, Hippasteria phrygiana, and Henricia lisa) and one gastropod (Buccinum scalariforme) from the bathyal Northwest Atlantic were investigated using video trials in darkened laboratory conditions. A range of competitive or cooperative behaviours occurred, depending on species (conspecific or heterospecific), comparative body size, and the number of individuals involved. Contrary to expectations , small individuals (or smaller species) were not always outcompeted by larger individuals (or larger species) when foraging and feeding. Moreover, faster species did not always outcompete slower ones while scavenging. Overall, this study sheds new light on scavenging strategies of co-existing deep-sea benthic species in food-limited bathyal environments, based on complex behavioural inter-and intraspecific relationships.
... Coastal areas are important habitats for many marine fish, and there are often large gradients in environmental conditions that result in different species assemblages [58]. Depth is an important variable in estuarine ecosystems and is closely related to the distribution of marine organisms, light intensity, food availability, and temperature [59]. In this study, the range of depths in the Yangtze Estuary is 23-62 m, with large spatial variation driving spatial variation in fish assemblages, but no significant interannual variation in time. ...
The offshore waters of the Yangtze Estuary are an important fish habitat, and the large gradient of environmental conditions leads to different fish assemblages. We studied the spatial and temporal variations in fish assemblages and their relationships with environmental factors in the offshore waters of the Yangtze Estuary during the autumns of 2012–2016. The fish assemblage consisted of 64 fish species from 39 families, of which 6 species were dominant. There were significant interannual differences in fish abundance, biomass, and species composition, with the highest abundance and biomass in 2013, the lowest abundance in 2016, and the lowest biomass in 2015. Redundancy analysis revealed that total suspended particles and dissolved oxygen drove interannual variation in fish abundance, biomass, and species composition, and depth drove spatial variation in the fish assemblage. According to the depth, the fish were classified as shallow assemblage and deep assemblage. Understanding the spatial and temporal patterns of fish assemblage in the offshore waters of the Yangtze Estuary is beneficial to the conservation of fish and the sustainable use of fishery resources in the offshore waters of the Yangtze Estuary.
... Biotope ZA is the strongest potential list candidate. It also bears some resemblance to a community identified on the Tail of the Grand Bank in the NW Atlantic dominated by Eucratea loricata and hydroids from the same family as Thuiaria (Murillo et al., 2016). Table 5 shows that it qualifies in terms of its limited spatial distribution, high biological productivity, and naturalness, with Table 4 clarifying that there are three descriptors contributing to these assessments. ...
Due to various intergovernmental agreements, marine managers must establish marine conservation measures to prevent the destruction of conservation-relevant benthic habitats e.g. Vulnerable Marine Ecosystems (VME). To aid this process, international “lists” of indicator species and habitats are created based on various conservation “criteria”. As these lists are both generalised and under development, there is a need to create comparable (management) regional lists to ensure regional relevance and to propose new international “list candidates”. This study provides a method to assess management region relevant (hereafter “regional”)/new benthic biotopes for conservation-relevance. Quantitative criteria-linked descriptors (e.g. species richness, predicted area occupancy, etc) are used to rank biotopes, enabling a comparison between listed and new biotopes. This highlights comparatively high-ranking new biotopes as potentially conservation-relevant. In a Norwegian case study, applied to the Barents Sea management region using data from the MAREANO programme, the criteria from three international frameworks (EBSA/Azores, FAO/VME, OSPAR/Texel Faial) are assessed with descriptors obtainable from existing or future baseline datasets (video survey data, biotope classifications, and predictive biotope maps). Here, the method correctly ranks existing listed biotopes highly but it also identifies, for example, a previously unlisted biotope as potentially conservation relevant (Cucumaria sea cucumbers, Eucratea bryozoans, and Thuiaria hydroids on coarse bottoms with highly variable conditions). This biotope is now accepted as having regional significance warranting national conservation attention. The dominant bryozoan has also since been listed as a FAO VME indicator within ICES/NEAFC. Although demonstrated in a region with an outstanding dataset, the method is transferable to anywhere with partial baseline data that can inform biotope classification.
... To date, only a few studies have addressed the effects of direct and indirect anthropogenic pressures, such as bottom fisheries and climate change, on deep-sea sponge habitats (Murillo et al., 2016;Beazley et al., 2018;Beazley et al., 2020). Morrison et al. investigated the recovery of sponge ground communities of an Arctic seamount (Schulz Bank) four years after physical disturbance by (experimental) bottom trawling. ...
... Halipteridae Halipteris cf. christii: Flexible, whip-like growth form; height 12 cm (Nutting 1912 Murillo et al. 2012Murillo et al. , 2016b Phakellia robusta: Thin upright fan-shaped sponge. Fuller 2011 Phakellia spp.: Erect cup or fan-shaped sponge with stalk; height 20 cm (Best et al. 2010). ...
... Bladder-like or club shaped sponge; height 5.5 cm, width 2.5 cm (Plotkin et al. 2018, Dinn & Leys 2018). Best et al. 2010, Plotkin et al. 2018, Dinn & Leys, 2018 Quasillina richardi Murillo et al. 2016b (Best et al. 2010). Best et al. 2010, Fuller 2011, Plotkin et al. 2018, Dinn & Leys, 2018, V. Hayes pers. ...
... Two species are proposed as new records at the area of study. Radiaster tizardi has been collected in adjacent waters (Murillo et al., 2016;Clark and Downey, 1992), and it was a potential species for living in the SCA. Henricia sexradiata distribution area is restricted to Gulf of Mexico and Caribbean Sea. ...
The Avilés Canyon System (ACS) is located at the Southern Bay of Biscay (Northern Spain, Cantabrian Sea). The ACS occupies a total of 339.026 ha and is composed of three canyons, reaching the abyssal plain at 4700 m depth. Water masses that mix in the area form gyres and upwelling that contribute to increasing the nutrients at different depths, which makes it an important place for the settlement of benthic communities. They have been declared Site of Community Importance (SCI: C ESZZ12003) within the Natura 2000 Network and recognized as a Vulnerable Marine Ecosystem where Echinoderms play an important role in these communities and habitats.
The present study tries to inventory and review asteroid fauna collected during the INDEMARES project in the ACS and compare the new findings with previous studies Official Spanish Checklist (IEEM: “Inventario Español de Especies Marinas”, 2017, 2020) to update our knowledge on the diversity and distribution of the asteroid's species.
During the surveys carried out within the project LIFE + INDEMARES-Avilés Canyon System (2010–2012) a total of 445 specimens, belonging to 25 Asteroids species, were collected from 36 stations in a depth range between 266 and 1476 m. The most frequent species were Nymphaster arenatus (Perrier, 1881) (30.55%) and Henricia caudani (Koehler, 1895) (25%). After public datasets, two species should be considered as new records for Spanish waters: Radiaster tizardi (Sladen, 1882) and Henricia sexradiata (Perrier, 1881), and 4 species expand their bathymetric range: Novodinia pandina (Sladen, 1889), H. caudani, H. sexradiata (Perrier, 1881) and Myxaster perrieri Koehler, 1895.
... The trawling impact on the target habitat was analysed using data from the 2007 EU Flemish Cap bottom-trawl research survey (Durán Muñoz, et al., 2020), using standardised sets of a Lofoten bottom trawl (with a swept area of ≈0.04 km 2 each) following a depth-stratified sampling design. For more information about the sampling area or method see Murillo et al., (2016Murillo et al., ( , 2020. After filtering out hauls located in the depth range of the selected MSFD broad habitat (600-1300 m), and removing 4 hauls located in the south side of the bank, 26 hauls distributed across a trawling gradient were analysed; 6 of them were located in no pressure areas (0 pings by km 2 ), 5 in low pressure (0.1-0.15 pings by km 2 ), 8 in medium pressure (0.16-0.5 pings by km 2 ), 4 in high pressure (0.6-2 pings by km 2 ) and 3 in very high pressure (>2.1 pings by km 2 ). ...
Indicators are key tools used to assess the ecological status of the environment for ecosystem based management. Anthropogenic disturbances produce changes to habitat condition, which include modifications in species composition and their functions. Monitoring a group of sentinel species (from a taxonomic and functional point of view) provides useful insights into benthic habitat condition. Here, a new indicator, Sentinels of the Seabed (SoS) is proposed to assess state of benthic habitats using “sentinel” species (species which are characteristic of a habitat and sensitive to a given pressure). The selection of these sentinel species has two stages. First, a ‘typical species set’ is computed using intra-habitat similarity and frequency under reference conditions. Second, the ‘sentinel species set’ is generated by selecting the most sensitive species from the typical species set. This selection is made using specific indexes able to assess species sensitivity to a particular pressure. The SoS indicator method was tested on six case studies and two different pressure types (trawling disturbance and pollution), using data from otter trawl, box-corer and Remote Operate Vehicle images. In each scenario, the SoS indicator was compared to the Shannon-Wiener diversity index, Margalef index and total biomass, being the only metric, which showed the expected significant negative response to pressure in all cases. Our results shows that SoS was highly effective in assessing benthic habitats status under both physical and chemical pressures, regardless of the sampling gear, the habitat, or the case study, showing a great potential to be a useful tool in the management of marine ecosystems.
... Distribution Caribe Sea, Venezuela, Present study: Argentine. (Clark and Downey, 1992;Murillo et al. 2016) presents moderate arm length (R/r = 2.2/1-3.0/1) and a large madreporite (Fig. 2m-o), while R. elegans presents long arms and a small madreporite. ...
The main target of this paper is to improve the knowledge of the species composition of sea stars in Patagonian Argentine deep sea reaching depths of 2062 m. In addition, these results offer us the opportunity to analyze the possible connections between Argentinian marine fauna and adjacent Antarctic areas that have become a topic of interest in the past few years. This work is based on Atlantic Projects’ surveys carried out on an atypical and especially vulnerable marine ecosystems (canyons created from craters collapse by gas leaks). These are profusely impacted by frequent fishing activities, being one of the most important and international fishing grounds, where 887 records (1878 specimens) of 41 species of asteroids were collected in 217 stations ranging from 219 to 2062 m in depth. Seven of those species are proposed as new records: (Diplasterias octoradiata (Studer 1885), Plutonaster bifrons (Wyville Thomson, 1873), Radiaster elegans Perrier, 1881, Anseropoda antarctica Fisher, 1940, Pillsburiaster calvus Mah, 2011, Paralophaster lorioli (Koehler, 1907), Pteraster flabellifer Mortensen 1933). After refining the database built from literature and open-access databases such as OBIS and AntBIF, the new Argentinian asteroids deep-water checklist contains 2198 records from 64 asteroids species including the 7 new records proposed. Most of these 64 species (89.06%) are present in Antarctic-adjacent waters, and after the study of their occurrences at traditional biogeographic entities, our results support the hypothesis that Argentinian waters (in the case of the class Asteroidea) should be considered part of the sub-Antarctic entity.
... punctata, and Telopathes magna as VME Indicator taxa, although some of these may be seamount species. Murillo et al. (2016) report the presence of Stichopathes sp. and Stauropathes arctica from the Flemish Cap and Grand Bank region. Wagner et al. (2011) have reviewed the reproductive biology of antipatharians. ...
... The only bryozoan indicator taxon listed in the NAFO CEMs is the feathery bryozoan, Eucratea loricata (NAFO, 2021). Eucratea loricata zooids form a tree-like colony up to 25 cm in height (Avant, 2004) and they occur generally at depths less than 100 m with Murillo et al. (2016) reporting its presence in 21 trawl sets from surveys done on Grand Bank in 2007 between 46-86 m. As for the other deep-sea VME indicator taxa, very little is known about the reproductive biology of this species. ...
... If H. pyriformis is present in the NRA it likely has similar reproductive traits to its Pacific congeners whose larvae metamorphose quickly, with oral and atrial siphons of settled juveniles appearing 23 days post fertilization at 11℃. Larval development is slower at low temperatures and more rapid at high temperatures (Kim, 2020). Murillo et al. (2016) recorded the presence of Halocynthia sp. 1 in one trawl from the Grand Bank during a detailed examination of the 2007 trawl catch from the Spanish surveys. Therefore, if present, the species is likely not common. ...
NAFO has used kernel density analyses to identify VMEs dominated by large-sized sponges, sea pens, small and large gorgonian corals, erect bryozoans, sea squirts (Boltenia ovifera), and black corals. That analysis generates polygons of significant concentrations of biomass for each VME indicator which are spread across the spatial domain of the NAFO fishing footprint. There is potential for bottom contact fishing to induce changes in both the amount and configuration of habitat (e.g., decreased polygon size, increased polygon isolation, and increased edge area) through direct and indirect impacts, and it is unknown to what degree such changes may already have taken place given the long fishing history of the area. In the Report of the 13th Meeting of the NAFO Scientific Council Working Group on Ecosystem Science and Assessment (WGE-ESA), preliminary work on assessing and monitoring habitat fragmentation was presented. Here we continue that work by recalculating the indices after removing connections that are not identified through particle tracking models. We have reanalyzed the nearest neighbour distances and PX, a proximity index, for the VME polygons noted above, and for the new closed areas that will come into effect 1 January 2022. We show that PX when applied to the new closures appears sensitive to their spatial configuration which bodes will for the ability of this index to identify habitat fragmentation in the future, brought about through fishing activities and/or natural disturbances.
... It was found together with several polymastiid species and Phakellia bowerbanki, forming a similar assemblage to those Phakellia-dominated sponge assemblages from the northern continental shelf of Norway (Kutti et al. 2013(Kutti et al. , 2015. Mycale (Mycale) lingua has been found at the top of the Flemish Cap and the upper slope of the Grand Banks on sandy and silty-sand bottoms with gravel at 130-666 m depth (Murillo et al., 2016). This species is also common in the Bay of Fundy in shallow waters (Goodwin, 2017). ...
... Mycale (Mycale) loveni is a commonly encountered species in North Pacific waters and the type specimen was collected in the Chukchi Sea along the Arctic Ocean margin (Fristedt, 1887). However, it has also been recorded in the northwest Atlantic (Fuller, 2011;Murillo et al., 2016 (Dinn et al. in prep.). ...
Sponges (phylum Porifera) are benthic filter feeding animals that play an important role in nutrient cycling and habitat provision in the deep sea. Sponges collected between 2010 and 2014 during annual multispecies trawl surveys conducted by Fisheries and Oceans Canada in Baffin Bay, Davis Strait and portions of Hudson Strait were taxonomically examined. In total ~2500 specimens were identified, comprising ~100 known sponge taxa. Sponges from the order
Poecilosclerida comprised nearly half of the identified species. Sponges from the poescilosclerid families Coelosphaeridae, Crellidae, Dendoricellidae, Myxillidae, Tedaniidae, Microcionidae, Acarnidae and Esperiopsidae are described in previous reports. This report adds descriptions of five sponge species from two poescilosclerid families: Mycalidae and Isodictyidae (class Demospongiae, subclass Heteroscleromorpha, order Poecilosclerida). Described species include Mycale (Mycale) lingua, Mycale (Mycale) cf. toporoki, Mycale (Mycale) cf. loveni and Mycale (Rhaphidotheca) marshallhalli, all from the family Mycalidae, and Isodictya aff. palmata from
the family Isodictyidae. Descriptions include physical description of the sponges, descriptions and dimensions of their spicules, and taxonomic discussion.
