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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. 

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. 

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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...

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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

... 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 ). ...
Article
Full-text available
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. ...
Article
Full-text available
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. ...
Technical Report
Full-text available
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.). ...
Technical Report
Full-text available
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.
... Specific traits linked to four important ecological functions provided by benthic communities were identified for initial consideration: A) Bioturbation; B) Nutrient cycling; C) Habitat provision, and D) Functional diversity. Murillo et al., 2016). It was conducted on board the Spanish research vessel Vizconde de Eza, with standardized sets of a Lofoten bottom trawl, with a swept area of ≈0.04 km 2 each. ...
... They observed that 63% of the species lived longer than 10 years (and 31% more than 50 years) and that 25% of the species had lifespans of less than 5 years. Additionally, from the 285 taxa, they selected those taxa that constituted 95% of the biomass from each community (Murillo et al., 2016) complemented by the top 20 taxa based on occurrence to account for common species with low biomass (105 taxa). Of this selection, based on taxa with high biomass or occurrence, 75% live more than 10 years. ...
... This area contrasts sharply with the top ranking species on Flemish Cap, where two VME indicator sea pens, Anthoptilum and Halipteris finmarchica contribute most to the biomass and influence the delineation of the KDE invertebrate bioturbation polygons there. These results are consistent with the Flemish Cap being a unique ecosystem in terms of its benthos (Murillo et al., 2016). ...
Technical Report
Full-text available
In support of the 2021/2022 NAFO review of the closed areas to protect vulnerable marine ecosystems (VMEs) in the NAFO Regulatory Area, previously established kernel density estimation (KDE) methods were applied to four important ecological functions provided by benthic communities: A) Bioturbation; B) Nutrient cycling; C) Habitat provision; and D) Functional diversity (FRic), in order to evaluate significant adverse impacts of NAFO bottom-contact fishing on vulnerable marine ecosystems against the wider benthic contributions to those functions. Fish and invertebrate species recorded in the EU and Canadian surveys from 2011-2019 were classified a priori as contributing to each of bioturbation, nutrient cycling and habitat provision functions, using literature references. The resultant catch biomass data for each function were examined using K-S statistics and cumulative biomass distribution plots to determine whether data from the different surveys could be combined. With few exceptions the surveys were analyzed separately and the KDE polygons overlain a posteriori to produce combined polygon areas for each function. A suite of species were important contributors to the biomass of catches used to delineate each of the KDE polygons. For bioturbation, the sea cucumber Cucumaria frondosa and sea pens, both considered surficial modifiers, contributed most to the biomass. Nutrient cycling and habitat provision functions were delineated by catches where sponges dominated the biomass. Details of the analyses and the species that contributed to the delineation of the polygons are provided. Functional diversity was not assessed as information needed on a wide variety of traits and modalities was not completed. However published data from a survey in 2007 of Division 3M was used to run the KDE analyses with equivocal results. The KDE polygons generated matched published maps of FRic created using the same data and interpolated using random forest modeling. However the data were not sufficiently aggregated to allow for a clear KDE threshold to be determined. All other KDE analyses performed well and showed good congruence to the published maps of their corresponding functions.
... This whole area is very productive and is associated with rich fisheries (Wang and Greenan, 2014). It is an area abundant in sponge grounds (predominantly Geodiidae) and other vulnerable marine ecosystem indicators including gorgonians, sponges, and sea pens (Knudby et al., 2013a,b;Murillo et al., 2016). These structure-forming organisms likely influence the number of micro-niches available to the other fauna living there, for example through providing hiding places for smaller organism, increasing the food availability in the area around them, and by being important nursery habitats for fish and invertebrates (Bett and Rice, 1992). ...
... There was a lot of variability in the south of the Grand Banks, indicated by the numerous small groups, while the larger groups showed either more localised grouping (to the north of the Flemish Cap and in the Flemish Pass) or seem to follow the Grand Banks contour at a consistent depth band. These patterns correspond somewhat with epibenthic megafaunal assemblages identified by Murillo et al. (2016), where different assemblages are structured based on depth bands around the Flemish Cap, and south of the tail of the Grand Banks, where steep slopes result in a smaller spatial separation horizontally of the different assemblages. Several environmental variables together ...
... other studies (Díaz-Castañeda and Harris, 2004;Barrio Froján et al., 2012;Lourido et al., 2014;Breine et al., 2018). Epibenthic megafaunal assemblages in the area could also be well explained by sediment (mud, in this case; Murillo et al., 2016). Here, there are differences in the percentage silt between the groups (ranging from 13 to 69% average for the groups). ...
Article
Many biodiversity patterns across the globe can be partially explained by energetics and habitat structure, including in the deep sea. Because of difficulties in logistics, studies focusing on deep-sea benthic systems often have limited sample sets that may be far apart in space. Here, we present analyses based on a well-sampled region, the northwest Atlantic, allowing us to relate patterns of polychaete community structure (using taxonomic families and feeding guilds) against well-resolved environmental gradients. We show that community structure is heterogenous in this area. We observe three major groups within polychaete communities which also show differences in feeding guilds. Several environmental gradients, including long-term variables, explained the differences between the groups. Both energetics and habitat structure variables were important, while past fishing intensity had a weak effect, although there was support for a difference in community composition for communities above and below the historical fishing limit of 1200 m. The effect of long-term environmental factors may indicate that the deep sea is not immune to climate change, and these effects must continue to be considered in future management of exploitation of this ecosystem.
... Throughout its distribution range, C. frondosa is commonly found from the lower intertidal zone to depths around 300 m (Jordan 1972;Patricio and Dearborn, 1989;Singh et al. 1998;Grant 2006;So et al. 2010;Teac a et al. 2017); however, some individuals have been collected between 500 and 1,000 m (Thouzeau et al. 1991;Murillo et al. 2016), and as deep as 1,450 m along the continental slope of eastern Canada (Ross et al. 2013). The highest abundance of C. frondosa is typically found at depths from 30 to 60 m ( Klugh 1923;Coady;Hamel and Mercier 1996a ) (see Section 3.9.2 for details on population structures). ...
Article
The demand and high market price for sea cucumber has led to the collapse of wild stocks for many traditional species in Asia and the Indo-Pacific. New species have therefore been introduced to the markets over recent decades, including Cucumaria frondosa. A fishery for C. frondosa emerged in the USA in the 1980s and quickly developed in Iceland, Canada and Russia. Commercial products include frozen and dry body wall (beche-de-mer), frozen muscle bands, dry aquapharyngeal bulb (flower), along with various pharmaceutical and nutraceutical extracts. This species is also a candidate for aquaculture due to its high marketability for food and bioactive products. Despite its naturally high abundance, C. frondosa is a temperate- polar slow-growing species with annual spawning; therefore, a precautionary approach must be taken to develop best practices for management of this resource. The present contribution reviews the biology, ecology, biochemical properties, harvesting and trade, and the potential aquaculture of C. frondosa. This comprehensive synthesis, including 10 theses, 197 scientific papers and 47 reports, aims to provide a framework for future research by highlighting areas of concern for academic studies, fishery management, and aquaculture of cold-water sea cucumber species.
... A large majority of larvae were found to stay around the parental habitat in the demersal water layer 43,44 , and in our models, we released particles from the seabed of each of the six closed areas. Eight of the 14 closed areas (Areas 2, 7-12 and 14) were closed to protect sea pens in the relatively shallower waters of Flemish Cap, with the species forming a distinct community on sandy and silt bottoms in the study area 42 . There is some information on the spawning season for some species or their congeneric representatives 7 but in general little is known about the reproductive biology of the 13 sea pen VME indicator taxa known to occur on Flemish Cap 45 . ...
Article
Full-text available
Novel 3-D passive particle tracking experiments were performed in the northwest Atlantic to elucidate connectivity among areas closed to protect vulnerable marine ecosystems. We examined (1) the degree of vertical movement of particles released at different depths and locations; (2) the location of potential source populations for the deep-sea taxa protected by the closures; and (3) the degree of functional connectivity. A long-term oceanographic dataset (EN4) was queried to characterize the temperature and salinity regimes in each of the closed areas as a basis for interpreting recently published climate change projections. Using the Parcels Lagrangian particle tracking framework and the BNAM hydrodynamic model, we found enhanced connectivity over previously developed 2-D models and unexpected, current-driven, strong (to a maximum of about 1340 m) downward displacement at depth (450, 1000 and 2250 m), with weaker upward displacement except for the release depth of 2250 m which showed upward movement of 955 m with a drift duration of 3 months. The current velocities create down-stream interdependence among closed areas and allow redundancy to develop in some of the areas of the network, with some of the larger areas also showing retention. Source populations for sponges in the upstream closure are likely in adjacent waters of the Canadian continental shelf. Collectively this information can be used to inform management decisions related to the size and placement of these closed areas, and vertical velocity surfaces have potential for use in species distribution modeling of benthic species and habitats.
... It is often composed from discrete observations over small areas, and over short time scales. This is in contrast to more comprehensive knowledge for coastal ecosystems regarding aspects like the spatial distribution of habitats, the natural variability of ecosystems (at short and long temporal scales), the extent and intensity of multiple human activities and the resilience of ecosystems to human pressures (Glover et al., 2010;Ramirez-Llodra et al., 2011;Murillo et al., 2016;OSPAR, 2017;Dailianis et al., 2018;Miloslavich et al., 2018;Pham et al., 2019). Moreover, information about the distribution of multiple human pressures across the deep sea (Benn et al., 2010;Pham et al., 2014) and experimental work about the response and resilience of deep-sea species and habitats to multiple human pressures is also very limited (Lunden et al., 2014;Büscher et al., 2017;Levin et al., 2019). ...
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The deep sea is the largest biome on Earth but the least explored. Our knowledge of it comes from scattered sources spanning different spatial and temporal scales. Implementation of marine policies like the European Union's Marine Strategy Framework Directive (MSFD) and support for Blue Growth in the deep sea are therefore hindered by lack of data. Integrated assessments of environmental status require tools to work with different and disaggregated datasets (e.g. density of deep-sea habitat-forming species, body-size distribution of commercial fishes, intensity of bottom trawling) across spatial and temporal scales. A feasibility study was conducted as part of the four-year ATLAS project to assess the effectiveness of the open-access Nested Environmental status Assessment Tool (NEAT) to assess deep-sea environmental status. We worked at nine selected study areas in the North Atlantic focusing on five MSFD descriptors (D1-Biodiversity, D3-Commercial fish and shellfish, D4-Food webs, D6-Seafloor integrity, D10-Marine litter). The objectives of the present study were to i) explore and propose indicators that could be used in the assessment of deep-sea environmental status, ii) evaluate the performance of NEAT in the deep sea, and iii) identify challenges and opportunities for the assessment of deep-sea status. Based on data availability, data quality and expert judgement, in total 24 indicators (one for D1, one for D3, seven for D4, 13 for D6, two for D10) were used in the assessment of the nine study areas, their habitats and ecosystem components. NEAT analyses revealed differences among the study areas for their environmental status ranging from "poor" to "high". Overall, the NEAT results were in moderate to complete agreement with expert judgement, previous assessments, scientific literature on human-pressure gradients and expected management outcomes. We suggest that the assessment of deep-sea environmental status should take place at habitat and ecosystem level (rather than at species level) and at relatively large spatial scales, in comparison to shallow-water areas. Limited knowledge across space (e.g. distribution of habitat-forming species) and the scarcity of long-term data sets limit our knowledge about natural variability and human impacts in the deep sea preventing https://doi.
... In the present study, we examined a substantial sampling of similar-looking actiniid sea anemones collected along the coast of Newfoundland (eastern Canada) from the same general location and habitat. Morphological and genetic investigations showed that they belonged to two different species: Cribrinopsis similis Calgren 1921 and Urticina crassicornis (Müller 1776), which are known from European and North American coasts of the North Atlantic (Carlgren 1921;Verrill 1922;Fautin 2013;Murillo et al. 2016). However, the analyses failed to find any U. felina and examination of published pictures suggest that specimens previously identified as U. felina in this region instead belong to the species C. similis. ...
... The two species described in the present paper, Cribrinopsis similis and Urticina crassicornis, are rather common and widely distributed, and they are known from the 20-40 × 2-4 (I) basitrichs (few) 50-62 × 4-5 (J) p-mastigophores A (common) 23-32 × 4.5-6.5 (K) p-mastigophores B1 (numerous) 24-39 × 4-7 Endoderm of column Basitrichs (very rare) 29-34 × 1.5-2 Basitrichs (very rare) 11-15 × 2-2.5 American and European coasts of the North Atlantic as well as from all northern European seas. Both species were previously reported from Newfoundland (Carlgren 1921;Murillo et al. 2016). Despite records for the two species in the World Register of Marine Species (WoRMS) showing clear geographic distributions encompassing a large part of the North Atlantic in Europe, eastern USA and Canada, the bulk of the literature on large sea anemones refers to U. felina. ...
... The occurrence of U. felina in the focal region (and in the NW Atlantic in general) is doubtful based on the lack of definitive taxonomic record discussed earlier. Despite the extensive distribution presented in WoRMS for this species (Daly and Fautin 2018), it was not found in the present survey or in a previous investigation that looked at material from trawl collections in Newfoundland (Murillo et al. 2016). Urticina felina differs from both U. crassicornis and C. similis by very well-developed and strongly adhesive verrucae on the column, which invariably have particles of gravel and other debris stuck to them, a contracted anemone having the appearance of a rounded mound of gravel (see Manuel 1988 and Fig. 10 showing specimens from Europe). ...
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Literature records of large actiniid sea anemones along the Atlantic coast of Canada currently include three Urticina species: U. felina, U. fecunda and U. crassicornis. The findings of the present morphological and molecular study conducted in eastern Newfoundland suggest that U. felina is often misidentified, and that this region may only harbor two similar-looking species: U. crassicornis and Cribrinopsis similis. The latter were identified using genetic analysis and comparison of key characters with the same species collected from other regions of the North Atlantic (Barents Sea), whereas no specimen corresponding to U. felina was found. Mitochondrial gene sequences of U. crassicornis, U. felina and C. similis were identical except for a different haplotype found in several specimens of U. crassicornis (with one nucleotide substitution), in contrast to five nucleotide insertions in 16S rRNA fragments of U. fecunda. Phylogenetic analysis based on three mitochondrial and two nuclear gene fragments revealed that the most closely related species among the above-mentioned were U. crassicornis and U. felina, nevertheless U. fecunda groups in the same clade as the Urticina species.