scholarly journals Dramatic decline and limited recovery of a green crab (Carcinus maenas) population in the Minas Basin, Canada after the summer of 2013

2018 ◽  
Author(s):  
Brady K. Quinn
Keyword(s):  
Gulf Of Maine ◽  
Carcinus Maenas ◽  
Monitoring Program ◽  
Marine Species ◽  
Bay Of Fundy ◽  
Catch Per Unit Effort ◽  
Spring Precipitation ◽  
Spring Temperature ◽  
Wind Speeds ◽  
Causative Agents

This paper reports the results of a ten-year monitoring program of an Atlantic Canadian population of green crabs, Carcinus maenas, in the Minas Basin of the Bay of Fundy. Intertidal densities, sex and reproductive ratios, juvenile recruitment, subtidal catch-per-unit-effort (CPUE), and sizes of crabs in this population were recorded from 2008 to 2017. In 2013 intertidal densities, mean crab sizes, subtidal CPUE, and proportions of crabs mature and reproducing all dramatically decreased to all-time lows, and large crabs virtually disappeared from the population. From 2014 to 2017 the population partially recovered but remained in an altered state. Potential causes of interannual changes to this population were investigated by correlating intertidal densities to 67 seasonal environmental variables. Crab densities in a given year were best explained by potential settlement, mean and variability of autumn, spring, and summer wind speeds, winter and spring temperature, and spring precipitation. However, potential roles of other factors (e.g., summer temperatures, North Atlantic Oscillation index) could not be ruled out. Changes in abundances of other species in the region, particularly predators and prey of green crabs, have also been observed and present possible alternative causative agents that should be investigated. Populations of other marine species in the Gulf of Maine-Bay of Fundy region within which the Minas Basin is situated have also been reported to have undergone dramatic changes in and after 2013, suggesting the occurrence of some oceanographic event or regime shift in the region. Declines to the monitored crab population in this study may have resulted from this same 2013 event. These observations have implications for recruitment to marine populations in this region.

scholarly journals Dramatic decline and limited recovery of a green crab (Carcinus maenas) population in the Minas Basin, Canada after the summer of 2013

2018 ◽  
Author(s):  
Brady K. Quinn
Keyword(s):  
Gulf Of Maine ◽  
Carcinus Maenas ◽  
Monitoring Program ◽  
Marine Species ◽  
Bay Of Fundy ◽  
Catch Per Unit Effort ◽  
Spring Precipitation ◽  
Spring Temperature ◽  
Wind Speeds ◽  
Causative Agents

This paper reports the results of a ten-year monitoring program of an Atlantic Canadian population of green crabs, Carcinus maenas, in the Minas Basin of the Bay of Fundy. Intertidal densities, sex and reproductive ratios, juvenile recruitment, subtidal catch-per-unit-effort (CPUE), and sizes of crabs in this population were recorded from 2008 to 2017. In 2013 intertidal densities, mean crab sizes, subtidal CPUE, and proportions of crabs mature and reproducing all dramatically decreased to all-time lows, and large crabs virtually disappeared from the population. From 2014 to 2017 the population partially recovered but remained in an altered state. Potential causes of interannual changes to this population were investigated by correlating intertidal densities to 67 seasonal environmental variables. Crab densities in a given year were best explained by potential settlement, mean and variability of autumn, spring, and summer wind speeds, winter and spring temperature, and spring precipitation. However, potential roles of other factors (e.g., summer temperatures, North Atlantic Oscillation index) could not be ruled out. Changes in abundances of other species in the region, particularly predators and prey of green crabs, have also been observed and present possible alternative causative agents that should be investigated. Populations of other marine species in the Gulf of Maine-Bay of Fundy region within which the Minas Basin is situated have also been reported to have undergone dramatic changes in and after 2013, suggesting the occurrence of some oceanographic event or regime shift in the region. Declines to the monitored crab population in this study may have resulted from this same 2013 event. These observations have implications for recruitment to marine populations in this region.

scholarly journals Dramatic decline and limited recovery of a green crab (Carcinus maenas) population in the Minas Basin, Canada after the summer of 2013

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5566 ◽  
Author(s):  
Brady K. Quinn
Keyword(s):  
Gulf Of Maine ◽  
Carcinus Maenas ◽  
Monitoring Program ◽  
Marine Species ◽  
Stepwise Multiple Regression ◽  
Bay Of Fundy ◽  
Catch Per Unit Effort ◽  
Canadian Population ◽  
Dramatic Decline ◽  
Causative Agents

This paper reports the results of a ten-year monitoring program of an Atlantic Canadian population of green crabs, Carcinus maenas, in the Minas Basin of the Bay of Fundy. Intertidal densities, sex and reproductive ratios, juvenile recruitment, subtidal catch-per-unit-effort (CPUE), and sizes of crabs in this population were recorded from 2008 to 2017. In 2013 intertidal densities, mean crab sizes, subtidal CPUE, and proportions of crabs mature and reproducing all dramatically decreased to all-time lows, and large crabs virtually disappeared from the population. From 2014 to 2017 the population partially recovered but remained in an altered state. Potential causes of interannual changes to this population were investigated by correlating intertidal densities to 257 monthly environmental variables and performing stepwise multiple regression analyses. Crab densities in a given year were best explained by potential settlement during the summer and the maximum sea-surface temperature during March of the same year. However, potential roles of other factors (e.g., autumn winds, summer temperatures, North Atlantic Oscillation index) could not be ruled out. Changes in abundances of other species in the area, particularly predators and prey of green crabs, have also been observed and present possible alternative causative agents that should be investigated. Populations of other marine species in the Gulf of Maine-Bay of Fundy region within which the Minas Basin is situated have also been reported to have undergone dramatic changes in and after 2013, suggesting the occurrence of some oceanographic event or regime shift in the region. Declines to the monitored crab population in this study may have resulted from this same 2013 event. These observations have implications for recruitment to marine populations in this region.

scholarly journals Habitat suitability modeling based on a spatiotemporal model: an example for cusk in the Gulf of Maine

2018 ◽  
Vol 75 (11) ◽  
pp. 1784-1797 ◽  
Author(s):  
Jocelyn Runnebaum ◽  
Lisha Guan ◽  
Jie Cao ◽  
Loretta O’Brien ◽  
Yong Chen
Keyword(s):  
Habitat Suitability ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Gulf Of Maine ◽  
Population Decline ◽  
Monitoring Program ◽  
Marine Species ◽  
Habitat Modeling ◽  
Density Estimates ◽  
Habitat Suitability Modeling

Habitat use and distribution is a critical aspect in the management and conservation of a species, particularly for those in decline. Habitat suitability indices (HSI) are a common method of habitat mapping dependent on empirical data that can easily lead to misunderstanding the spatiotemporal dynamics of marine species experiencing population decline and density-dependent catchability within surveys. This is especially true when only a single monitoring program with limited spatiotemporal coverage is used. A delta-generalized linear mixed model was used to combine trawl and longline surveys to predict density estimates for cusk (Brosme brosme) in unsampled locations for use in HSIs. Catchability was estimated for longline and trawl gear without having an estimate of area fished for the longline survey. HSIs performed better using model-based density estimates from multiple surveys compared with sample-based abundance indices from a single survey. The increased spatial resolution can better inform the HSIs by providing information where the survey programs did not sample. This study provides a novel approach for integrating data from different monitoring programs for habitat modeling.

Advancing an Ecosystem Approach in the Gulf of Maine

2012 ◽  
Keyword(s):  
Gulf Of Maine ◽  
Data Gathering ◽  
Ecosystem Approach ◽  
Bay Of Fundy ◽  
Fishing Industry ◽  
Full Potential ◽  
Georges Bank ◽  
The West ◽  
Management Guidance ◽  
Natural Foods

<i>Abstract</i>.—The Gulf of Maine (GoM) may have defined borders to some, but to the Canadian fishing industry, it carries a flow of larvae, nutrients, and other resources that help sustain the fishery from Georges Bank to the West Scotian Slope to the Bay of Fundy and all points in between. The GoM provides a source of wealth to people and communities, as well as supplying what may be one of the last natural foods on the planet. The fishing industry has been using the GoM for centuries, yet it is only recently that monitoring and data gathering has been taking place. In my opinion, we can extract much more value from the fisheries than we presently do. If the fisheries resource of the GoM is not delivering its full potential, who is ultimately responsible and accountable? In the past decade, transboundary groundfish resources from Georges Bank have been successfully managed through the Transboundary Management Guidance Committee. We can improve decision making even further in a greater ecosystem context, recognizing that decisions have to be made with the information available. An ecosystem approach to fisheries proposes a pragmatic view based on assessing the risk of not meeting agreed objectives.

Advancing an Ecosystem Approach in the Gulf of Maine

2012 ◽  
Keyword(s):  
Large Scale ◽  
Gulf Of Maine ◽  
Critical Role ◽  
Monitoring Program ◽  
Ecosystem Dynamics ◽  
Georges Bank ◽  
Scotian Shelf ◽  
Monitoring Programs ◽  
Zooplankton Dynamics ◽  
Biological Environment

<i>Abstract</i>.—Zooplankton communities perform a critical role as secondary producers in marine ecosystems. They are vulnerable to climate-induced changes in the marine environment, including temperature, stratification, and circulation, but the effects of these changes are difficult to discern without sustained ocean monitoring. The physical, chemical, and biological environment of the Gulf of Maine, including Georges Bank, is strongly influenced by inflow from the Scotian Shelf and through the Northeast Channel, and thus observations both in the Gulf of Maine and in upstream regions are necessary to understand plankton variability and change in the Gulf of Maine. Large-scale, quasi synoptic plankton surveys have been performed in the Gulf of Maine since Bigelow’s work at the beginning of the 20th century. More recently, ongoing plankton monitoring efforts include Continuous Plankton Recorder sampling in the Gulf of Maine and on the Scotian Shelf, U.S. National Marine Fisheries Service’s MARMAP (Marine Resources Monitoring, Assessment, and Prediction) and EcoMon (Ecosystem Monitoring) programs sampling the northeast U.S. Continental Shelf, including the Gulf of Maine, and Fisheries and Oceans Canada’s Atlantic Zone Monitoring Program on the Scotian Shelf and in the eastern Gulf of Maine. Here, we review and compare past and ongoing zooplankton monitoring programs in the Gulf of Maine region, including Georges Bank and the western Scotian Shelf, to facilitate retrospective analysis and broadscale synthesis of zooplankton dynamics in the Gulf of Maine. Additional sustained sampling at greater-than-monthly frequency at selected sites in the Gulf of Maine would be necessary to detect changes in phenology (i.e. seasonal timing of biological events). Sustained zooplankton sampling in critical nearshore fish habitats and in key feeding areas for upper trophic level organisms, such as marine mammals and seabirds, would yield significant insights into their dynamics. The ecosystem dynamics of the Gulf of Maine are strongly influenced by large-scale forcing and variability in upstream inflow. Improved coordination of sampling and data analysis among monitoring programs, effective data management, and use of multiple modeling approaches will all enhance the mechanistic understanding of the structure and function of the Gulf of Maine pelagic ecosystem.

Distribution of methanesulphonate, nss sulphate, so2 and dimethylsulphide over the bay of fundy and gulf of maine

1996 ◽  
pp. 427-430
Author(s):  
A.M. Macdonald ◽  
S.M. Li ◽  
K.G. Anlauf ◽  
S. Sharma ◽  
C.M. Banic ◽  
...  
Keyword(s):  
Gulf Of Maine ◽  
Bay Of Fundy

scholarly journals Biosecurity risks posed by a large sea-going passenger vessel: challenges of terrestrial arthropod species detection and eradication

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Simon J. McKirdy ◽  
Simon O’Connor ◽  
Melissa L. Thomas ◽  
Kristin L. Horton ◽  
Angus Williams ◽  
...  
Keyword(s):  
Monitoring Program ◽  
Marine Species ◽  
Indigenous Species ◽  
Terrestrial Arthropods ◽  
Arthropod Species ◽  
Detailed List ◽  
The Baltic ◽  
Passenger Vessel ◽  
Non Indigenous Species ◽  
Large Vessels

AbstractLarge sea-going passenger vessels can pose a high biosecurity risk. The risk posed by marine species is well documented, but rarely the risk posed by terrestrial arthropods. We conducted the longest running, most extensive monitoring program of terrestrial arthropods undertaken on board a passenger vessel. Surveillance was conducted over a 19-month period on a large passenger (cruise) vessel that originated in the Baltic Sea (Estonia). The vessel was used as an accommodation facility to house workers at Barrow Island (Australia) for 15 months, during which 73,061 terrestrial arthropods (222 species - four non-indigenous (NIS) to Australia) were collected and identified on board. Detection of Tribolium destructor Uytt., a high-risk NIS to Australia, triggered an eradication effort on the vessel. This effort totalled more than 13,700 human hours and included strict biosecurity protocols to ensure that this and other non-indigenous species (NIS) were not spread from the vessel to Barrow Island or mainland Australia. Our data demonstrate that despite the difficulties of biosecurity on large vessels, stringent protocols can stop NIS spreading from vessels, even where vessel-wide eradication is not possible. We highlight the difficulties associated with detecting and eradicating NIS on large vessels and provide the first detailed list of species that inhabit a vessel of this kind.

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