scholarly journals Ecological determinants of intertidal recruitment and metacommunity structure on the Atlantic coast of Nova Scotia

2018 ◽  
Author(s):  
Ricardo A. Scrosati ◽  
Julius A. Ellrich
Keyword(s):  
Nova Scotia ◽  
Atlantic Coast ◽  
Seawater Temperature ◽  
Rocky Intertidal ◽  
Late Winter ◽  
In Situ Data ◽  
Sessile Invertebrates ◽  
Filter Feeders ◽  
Metacommunity Structure ◽  
Rocky Habitats

Rocky-intertidal species are often distributed as metacommunities along marine shores, as rocky habitats are patchy. Nearshore pelagic conditions often explain variation among the local communities, but most studies have been done on eastern ocean boundary coasts. We investigated potential drivers of intertidal metacommunity structure on the Atlantic coast of Nova Scotia. We studied the high intertidal zone of nine wave-exposed bedrock locations spanning 425 km of coastline. At each location in the spring, we measured the recruitment of barnacles and mussels, the two predominant sessile invertebrates. Satellite data on coastal phytoplankton abundance and particulate organic carbon (food supply for intertidal filter-feeders) and in-situ data on coastal seawater temperature explained to varying degrees the geographic structure of recruitment. In turn, the summer abundance of both filter-feeders was positively related to their spring recruitment. Ultimately, predator (dogwhelk) abundance increased with the recruitment and abundance of barnacles and mussels (the main prey of dogwhelks), suggesting that bottom-up forcing influences metacommunity structure on this coast. Sea ice constituted an overlapping source of variation. Drift ice leaving the Gulf of St. Lawrence in late winter disturbed intertidal communities in the northern locations, limiting local biodiversity compared with central and southern locations.

scholarly journals Ecological determinants of intertidal recruitment and metacommunity structure on the Atlantic coast of Nova Scotia

2018 ◽  
Author(s):  
Ricardo A. Scrosati ◽  
Julius A. Ellrich
Keyword(s):  
Nova Scotia ◽  
Atlantic Coast ◽  
Seawater Temperature ◽  
Rocky Intertidal ◽  
Late Winter ◽  
In Situ Data ◽  
Sessile Invertebrates ◽  
Filter Feeders ◽  
Metacommunity Structure ◽  
Rocky Habitats

Rocky-intertidal species are often distributed as metacommunities along marine shores, as rocky habitats are patchy. Nearshore pelagic conditions often explain variation among the local communities, but most studies have been done on eastern ocean boundary coasts. We investigated potential drivers of intertidal metacommunity structure on the Atlantic coast of Nova Scotia. We studied the high intertidal zone of nine wave-exposed bedrock locations spanning 425 km of coastline. At each location in the spring, we measured the recruitment of barnacles and mussels, the two predominant sessile invertebrates. Satellite data on coastal phytoplankton abundance and particulate organic carbon (food supply for intertidal filter-feeders) and in-situ data on coastal seawater temperature explained to varying degrees the geographic structure of recruitment. In turn, the summer abundance of both filter-feeders was positively related to their spring recruitment. Ultimately, predator (dogwhelk) abundance increased with the recruitment and abundance of barnacles and mussels (the main prey of dogwhelks), suggesting that bottom-up forcing influences metacommunity structure on this coast. Sea ice constituted an overlapping source of variation. Drift ice leaving the Gulf of St. Lawrence in late winter disturbed intertidal communities in the northern locations, limiting local biodiversity compared with central and southern locations.

scholarly journals Ecological determinants of intertidal recruitment and metacommunity structure on the Atlantic coast of Nova Scotia

2018 ◽  
Author(s):  
Ricardo A. Scrosati ◽  
Julius A. Ellrich
Keyword(s):  
Nova Scotia ◽  
Atlantic Coast ◽  
Seawater Temperature ◽  
Rocky Intertidal ◽  
Late Winter ◽  
In Situ Data ◽  
Sessile Invertebrates ◽  
Filter Feeders ◽  
Metacommunity Structure ◽  
Rocky Habitats

Rocky-intertidal species are often distributed as metacommunities along marine shores, as rocky habitats are patchy. Nearshore pelagic conditions often explain variation among the local communities, but most studies have been done on eastern ocean boundary coasts. We investigated potential drivers of intertidal metacommunity structure on the Atlantic coast of Nova Scotia. We studied the high intertidal zone of nine wave-exposed bedrock locations spanning 415 km of coastline. At each location in the spring, we measured the recruitment of barnacles and mussels, the two predominant sessile invertebrates. Satellite data on coastal phytoplankton abundance and particulate organic carbon (food supply for intertidal filter-feeders) and in-situ data on coastal seawater temperature explained to varying degrees the geographic structure of recruitment. In turn, the summer abundance of both filter-feeders was positively related to their spring recruitment. Ultimately, predator (dogwhelk) abundance increased with the recruitment and abundance of barnacles and mussels (the main prey of dogwhelks), suggesting that bottom-up forcing influences metacommunity structure on this coast. Sea ice constituted an overlapping source of variation. Drift ice leaving the Gulf of St. Lawrence in late winter disturbed intertidal communities in the northern locations, limiting local biodiversity compared with central and southern locations.

scholarly journals Ecological determinants of intertidal recruitment and metacommunity structure on the Atlantic coast of Nova Scotia

2018 ◽  
Author(s):  
Ricardo A. Scrosati ◽  
Julius A. Ellrich
Keyword(s):  
Nova Scotia ◽  
Atlantic Coast ◽  
Seawater Temperature ◽  
Rocky Intertidal ◽  
Late Winter ◽  
In Situ Data ◽  
Sessile Invertebrates ◽  
Filter Feeders ◽  
Metacommunity Structure ◽  
Rocky Habitats

Rocky-intertidal species are often distributed as metacommunities along marine shores, as rocky habitats are patchy. Nearshore pelagic conditions often explain variation among the local communities, but most studies have been done on eastern ocean boundary coasts. We investigated potential drivers of intertidal metacommunity structure on the Atlantic coast of Nova Scotia. We studied the high intertidal zone of nine wave-exposed bedrock locations spanning 415 km of coastline. At each location in the spring, we measured the recruitment of barnacles and mussels, the two predominant sessile invertebrates. Satellite data on coastal phytoplankton abundance and particulate organic carbon (food supply for intertidal filter-feeders) and in-situ data on coastal seawater temperature explained to varying degrees the geographic structure of recruitment. In turn, the summer abundance of both filter-feeders was positively related to their spring recruitment. Ultimately, predator (dogwhelk) abundance increased with the recruitment and abundance of barnacles and mussels (the main prey of dogwhelks), suggesting that bottom-up forcing influences metacommunity structure on this coast. Sea ice constituted an overlapping source of variation. Drift ice leaving the Gulf of St. Lawrence in late winter disturbed intertidal communities in the northern locations, limiting local biodiversity compared with central and southern locations.

scholarly journals Recruitment and abundance of intertidal barnacles and mussels along the Atlantic Canadian coast: pelagic influences and relationships with predator abundance

2017 ◽  
Author(s):  
Ricardo A. Scrosati ◽  
Julius A. Ellrich
Keyword(s):  
Large Scale ◽  
Atlantic Coast ◽  
Seawater Temperature ◽  
Rocky Intertidal ◽  
Late Winter ◽  
In Situ Data ◽  
Prey Interaction ◽  
Filter Feeders ◽  
Benthic Pelagic Coupling ◽  
Ocean Boundary

AbstractBenthic species from rocky intertidal systems are irregularly distributed along marine coastlines. Nearshore pelagic conditions often help to explain such variation, but most such studies have been done on eastern ocean boundary coasts. Through a large-scale mensurative study, we investigated possible benthic-pelagic coupling along the Atlantic coast of Nova Scotia, a western ocean boundary coast. We studied the high intertidal zone of nine wave-exposed bedrock locations spanning 415 km of coastline from north to south. At each location in the spring, we measured the recruitment of barnacles and mussels, the two main filter-feeding invertebrates. Recruitment varied irregularly along the coast. Satellite data on coastal phytoplankton and particulate organic carbon (food for intertidal filter-feeders and their pelagic larvae) and in-situ data on seawater temperature explained, to varying degrees, the geographic structure of recruitment. In turn, the summer abundance of both filter-feeders was positively related to their spring recruitment. Ultimately, predator (dogwhelk) abundance was positively related to the recruitment and/or abundance of barnacles and mussels (the main prey of dogwhelks). These results are consistent with bottom-up forcing influencing intertidal community structure on this coast. Sea ice may also influence this predator–prey interaction. Drift ice leaving the Gulf of St. Lawrence in late winter disturbed the northern locations surveyed on the Atlantic coast, making barnacles (owing to their high spring recruitment) the only food source for dogwhelks at such places. Investigating the oceanographic drivers of pelagic food supply and seawater temperature should help to further understand how this large metacommunity is organized.

scholarly journals First visual record of rare purple-colored dogwhelks (Nucella lapillus) on the Atlantic coast of Nova Scotia, Canada

F1000Research ◽  
2017 ◽  
Vol 5 ◽  
pp. 2435
Author(s):  
Sonja M. Ehlers ◽  
Julius A. Ellrich
Keyword(s):  
Nova Scotia ◽  
Field Experiments ◽  
Atlantic Coast ◽  
Rocky Intertidal ◽  
Bay Of Fundy ◽  
Nucella Lapillus ◽  
Shell Color ◽  
The North ◽  
Intertidal Gastropod ◽  
Visual Record

The dogwhelk Nucella lapillus is a rocky intertidal gastropod of the North Atlantic coast. Individual shell color varies. Common colors range between white and brown, with darker dogwhelks being more affected by heat stress than lighter-colored conspecifics. Other reported shell colors are purple, black, mauve, pink, yellow, and orange from UK coasts, red and gray from the Bay of Fundy coast of New Brunswick and Nova Scotia (Canada), and purple, black, gray, yellow, and orange from the coasts of Maine and Massachusetts (USA), with purple being considered as a rare color. On the Atlantic coast of Nova Scotia, dogwhelks are active from April until November, but information on dogwhelk shell color is missing for this coast. On 16 June 2016, we found two purple-colored dogwhelks in the mid-to-high intertidal zone of a moderately wave-exposed rocky shore near Duncans Cove, on the Atlantic coast of Nova Scotia while collecting dogwhelks (n= 1000) during low tide for manipulative field experiments. All other dogwhelks collected on that day were of common white and brown colors. During earlier dogwhelk collections in Atlantic Nova Scotia (between 2011-2013) and field surveys in Duncans Cove (between 2014-2016), we did not find any purple-colored dogwhelks, indicating the rareness of this color in that region. Apparently, our observations provide the first visual record of rare purple-colored dogwhelks on the Atlantic coast of Nova Scotia, Canada.

scholarly journals First visual record of rare purple dogwhelks (Nucella lapillus) on the Atlantic coast of Nova Scotia, Canada

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 2435
Author(s):  
Sonja M. Ehlers ◽  
Julius A. Ellrich
Keyword(s):  
Nova Scotia ◽  
Field Experiments ◽  
Atlantic Coast ◽  
Rocky Intertidal ◽  
Bay Of Fundy ◽  
Nucella Lapillus ◽  
Shell Color ◽  
The North ◽  
Intertidal Gastropod ◽  
Visual Record

The dogwhelk Nucella lapillus is a rocky intertidal gastropod of the North Atlantic coast. Individual shell color varies. Common colors range between white and brown, with darker dogwhelks being more affected by heat stress than lighter-colored conspecifics. Other reported shell colors are black, mauve, pink, yellow, and orange from European coasts, red and grey from the Bay of Fundy coast of New Brunswick and Nova Scotia (Canada), and purple, black, gray, yellow, and orange from the coasts of Maine and Massachusetts (USA), with purple being considered as a rare color. On the Atlantic coast of Nova Scotia, dogwhelks are active from April until November, but information on dogwhelk shell color is missing for this coast. On 16 June 2016, we found two purple dogwhelks in the mid-to-high intertidal zone of a moderately wave-exposed rocky shore near Duncans Cove, on the Atlantic coast of Nova Scotia while collecting dogwhelks (n= 1000) for manipulative field experiments. All other dogwhelks collected on that day were of common white and brown colors. During earlier dogwhelk collections in Atlantic Nova Scotia (between 2011-2013) and field surveys in Duncans Cove (between 2014-2016), we did not find any purple dogwhelks, indicating the rareness of this color in that region. Interestingly, the purple dogwhelks were detected on a relatively cool day (12.3 ± 0.4 °C, mean ± se, n= 96 temperature measurements) compared to the intertidal temperatures of all other survey days (≥ 18.2 ± 0.5 °C), suggesting that purple dogwhelks may find it less thermally stressful to venture out of crevices and macroalgal cover under relatively cool temperatures. Our observations provide the first visual record of rare purple dogwhelks on the Atlantic coast of Nova Scotia, Canada.

scholarly journals Barnacle recruit density and size increase from high to middle intertidal elevations in wave-exposed habitats on the Atlantic coast of Nova Scotia

2019 ◽  
Author(s):  
Ricardo A Scrosati
Keyword(s):  
Nova Scotia ◽  
Interspecific Interactions ◽  
Atlantic Coast ◽  
Rocky Intertidal ◽  
Ne Atlantic ◽  
Relevant Role ◽  
Ne Pacific ◽  
Intertidal Habitats ◽  
High Elevations ◽  
Intertidal Environments

Barnacle recruitment is often studied in rocky intertidal habitats due to the relevant role that barnacles can play in intertidal communities. In 2014, barnacle (Semibalanus balanoides) recruitment was measured at high elevations in wave-exposed intertidal habitats on the NW Atlantic coast in Nova Scotia, Canada. Values were considerably lower than previously reported for middle elevations in wave-exposed intertidal habitats on the NE Atlantic and NE Pacific coasts. To determine if such differences in recruitment may have resulted from elevation influences, I did a field experiment in 2019 in wave-exposed intertidal habitats in Nova Scotia to test the hypothesis that recruitment is higher at middle than at high elevations, based on known environmental differences between both elevation zones. Based on data from three locations spanning 158 km of the Nova Scotia coast, barnacle recruitment was, on average, nearly 200 % higher (and recruits were larger) at middle than at high elevations. However, even with this increase, barnacle recruitment on this NW Atlantic coast is still lower than for comparable habitats on the NE Atlantic and NE Pacific coasts, and also lower than previously reported for wave-exposed locations farther south on the NW Atlantic coast, in Maine, USA. Therefore, barnacle recruitment in wave-exposed intertidal environments in Nova Scotia appears to be only moderate relative to other shores. This difference in the supply of barnacle recruits might influence the intensity of interspecific interactions involving barnacles.

The effect of temperature on development and reproduction in Chorda filum and C. tomentosa (Phaeophyta, Laminariales) from Nova Scotia

1986 ◽  
Vol 64 (11) ◽  
pp. 2414-2420 ◽  
Author(s):  
I. Novaczek ◽  
C. J. Bird ◽  
J. McLachlan
Keyword(s):  
Nova Scotia ◽  
Water Temperature ◽  
Temperature Regime ◽  
Water Surface ◽  
Atlantic Coast ◽  
Effect Of Temperature ◽  
Late Winter ◽  
Field Temperature ◽  
Dim Light ◽  
Young Sporophytes

The occurrence of sporophytes of Chorda tomentosa and C. filum in the southern Gulf of St. Lawrence was correlated with the field temperature regime. Temperature tolerances of gametophytes and young sporophytes of both species were tested in culture, using isolates from both the gulf and the outer Atlantic coast of Nova Scotia. Chorda tomentosa sporophytes appeared in late winter when the water surface was frozen, were fertile from April to June, and died when water temperature approached 20 °C. In culture, sporophytes tolerated −1 to 15 but became moribund at 20 °C. Gametophytes in constant temperature reproduced readily at 5 °C, occasionally at 0 and 10 °C, but not at higher temperatures; they survived to 24 °C. After 6 months in dim light at 10 °C some gametophytes also released gametes at 15 °C. Sporophytes of C. filum appeared in the field in spring after the water temperature had risen above 1 °C and persisted through the warm months. New sporophytes appeared in the autumn after the water temperature dropped below 15 °C but did not survive the winter. In culture, sporophytes died at −1 and 28 °C and survived between 0 and 24 °C. Gametophytes reproduced readily from 5 to 12, rarely at 0 and 15 °C, and not at higher temperatures. Gametophytes of both species survived 5 months in 0 ± 2 °C, [Formula: see text].

scholarly journals Changes in barnacle recruitment and recruit body size with intertidal elevation on wave-exposed rocky shores in Nova Scotia

2019 ◽  
Author(s):  
Ricardo A. Scrosati
Keyword(s):  
Nova Scotia ◽  
Interspecific Interactions ◽  
Atlantic Coast ◽  
Rocky Intertidal ◽  
Rocky Shores ◽  
Ne Atlantic ◽  
Relevant Role ◽  
Ne Pacific ◽  
Intertidal Habitats ◽  
High Elevations

AbstractBarnacle recruitment is often studied in rocky intertidal habitats due to the relevant role that barnacles can play in intertidal communities. In 2014, barnacle (Semibalanus balanoides) recruitment was measured at high elevations in wave-exposed intertidal habitats on the NW Atlantic coast in Nova Scotia, Canada. Values were considerably lower than previously reported for middle elevations in wave-exposed intertidal habitats on the NE Atlantic and NE Pacific coasts. To determine if such differences in recruitment may have resulted from elevation influences, I did a field experiment in 2019 in wave-exposed intertidal habitats in Nova Scotia to test the hypothesis that recruitment is higher at middle than at high elevations, based on known environmental differences between both elevation zones. Based on data from three locations spanning 158 km of the Nova Scotia coast, barnacle recruitment was, on average, nearly 200 % higher (and recruits were larger) at middle than at high elevations. However, even with this increase, barnacle recruitment on this NW Atlantic coast is still lower than for comparable habitats on the NE Atlantic and NE Pacific coasts, and also lower than previously reported for wave-exposed locations farther south on the NW Atlantic coast, in Maine, USA. Therefore, barnacle recruitment in wave-exposed intertidal environments in Nova Scotia appears to be only moderate relative to other shores. This difference in the supply of barnacle recruits might influence the intensity of interspecific interactions involving barnacles.

scholarly journals First visual record of rare purple dogwhelks (Nucella lapillus) on the Atlantic coast of Nova Scotia, Canada

2016 ◽  
Author(s):  
Sonja M. Ehlers ◽  
Julius A. Ellrich
Keyword(s):  
Nova Scotia ◽  
Field Experiments ◽  
Atlantic Coast ◽  
Rocky Intertidal ◽  
Bay Of Fundy ◽  
Nucella Lapillus ◽  
Shell Color ◽  
The North ◽  
Intertidal Gastropod ◽  
Visual Record

The dogwhelk Nucella lapillus is a rocky intertidal gastropod of the North Atlantic coast. Individual shell color varies. Common colors range between white and brown, with darker dogwhelks being more affected by heat stress than lighter-colored conspecifics. Other reported shell colors are black, mauve, pink, yellow, and orange from European coasts, red and grey from the Bay of Fundy coast of New Brunswick and Nova Scotia (Canada), and purple, black, gray, yellow, and orange from the coasts of Maine and Massachusetts (USA), with purple being considered as a rare color. On the Atlantic coast of Nova Scotia, dogwhelks are active from April until November, but information on dogwhelk shell color is missing for this coast. On 16 June 2016, we found two purple dogwhelks in the mid-to-high intertidal zone of a moderately wave-exposed rocky shore near Duncans Cove, on the Atlantic coast of Nova Scotia while collecting dogwhelks (n= 1000) for manipulative field experiments. All other dogwhelks collected on that day were of common white and brown colors. During earlier dogwhelk collections in Atlantic Nova Scotia (between 2011-2013) and field surveys in Duncans Cove (between 2014-2016), we did not find any purple dogwhelks, indicating the rareness of this color in that region. Interestingly, the purple dogwhelks were detected on a relatively cool day (12.3 ± 0.4 °C, mean ± se, n= 96 temperature measurements) compared to the intertidal temperatures of all other survey days (≥ 18.2 ± 0.5 °C), suggesting that purple dogwhelks may find it less thermally stressful to venture out of crevices and macroalgal cover under relatively cool temperatures. Our observations provide the first visual record of rare purple dogwhelks on the Atlantic coast of Nova Scotia, Canada.

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