scholarly journals Spatiotemporal Modeling of Bycatch Data: Methods and a Practical Guide through a Case Study in a Canadian Arctic Fishery

2021 ◽  
Author(s):  
Yuan Yan ◽  
Eva Cantoni ◽  
Chris Field ◽  
Margaret A Treble ◽  
Joanna Mills Flemming
Keyword(s):  
Fishery Management ◽  
Canadian Arctic ◽  
Marine Species ◽  
Conservation Strategies ◽  
Commercial Fishing ◽  
Spatiotemporal Modeling ◽  
Greenland Shark ◽  
Practical Guide ◽  
Exploratory Data ◽  
Spatio Temporal

Excess bycatch of marine species during commercial fishing trips is a challenging problem in fishery management worldwide. The aims of this paper are twofold: to introduce methods and provide a practical guide for spatio-temporal modelling of bycatch data, as well as to apply these methods and present a thorough examination of Greenland shark bycatch weight in a Canadian Arctic fishery. We introduce the spatially explicit two-part model and offer a step by step guide for applying the model to any form of bycatch data, from data cleaning, exploratory data analysis, variable and model selection, model checking, to results interpretation. We address various problems encountered in decision making and suggest that researchers proceed cautiously and always keep in mind the aims of the analysis when fitting a spatio-temporal model. Results identified spatio-temporal hotspots and indicated month and gear type were key drivers of high bycatch. The importance of onboard observers in providing robust bycatch data was also evident. These findings will help to inform conservation strategies and management decisions, such as limiting access to spatial hotspots, seasonal closures and gear restrictions.

scholarly journals Noteworthy occurrences among six marine species documented with community engagement in the Canadian Arctic

2021 ◽  
Vol 8 (1) ◽  
pp. 74-83
Author(s):  
Darcy G. Mc Nicholl ◽  
Les N. Harris ◽  
Tracey Loewen ◽  
Peter May ◽  
Lilian Tran ◽  
...  
Keyword(s):  
Stock Assessment ◽  
Pink Salmon ◽  
Canadian Arctic ◽  
Marine Species ◽  
Oncorhynchus Gorbuscha ◽  
Arctic Ecosystems ◽  
Greenland Shark ◽  
Novel Approach ◽  
Somniosus Microcephalus ◽  
New Occurrences

Abstract Arctic marine ecosystems are changing, one aspect of which appears to be distributional expansions of sub-arctic species. For Arctic marine systems, there is limited occurrence information for many species, especially those found in restricted habitats (e.g., ice-covered, far north, or deep-water). Increasing observations through on-going Fisheries and Oceans Canada (DFO) community-based monitoring programs (e.g., Arctic Coast, Cambridge Bay Arctic Char stock assessment, Arctic Salmon, and Kugluktuk coastal surveys), community observation networks, and local media have augmented opportunities to document new occurrences of marine fishes. Combined data from historical records and contemporary observations at the local scale can then delineate these among three types of occurrences: gradual distributional expansion, episodic vagrants, and rare endemics. Here we document nine occurrences of unusual sightings across six fish species (Pink Salmon Oncorhynchus gorbuscha, Bering Wolffish Anarhichas orientalis, Greenland Shark Somniosus microcephalus, Broad Whitefish Coregonus nasus, Banded Gunnel Pholis fasciata and Salmon Shark Lamna ditropis) from six northern Canadian communities and classify the nature of each observation as rare, vagrant, or expanding distributions. Uniting scientific and local observations represents a novel approach to monitor distributional changes suitable for a geographically large but sparsely populated area such as the Canadian Arctic. The new occurrences are important for discerning the potential effects of the presence of these species in Arctic ecosystems. These observations more broadly will build on our understanding of northern biodiversity change associated with warming Arctic environments.

Spatio-temporal variability of zoobenthic communities in a tectonic lagoon (Lake Vouliagmeni, Attika, Greece)

2008 ◽  
Vol 88 (5) ◽  
pp. 873-881 ◽  
Author(s):  
Chariton Chintiroglou ◽  
Chryssanthi Antoniadou ◽  
Panagiotis Damianidis
Keyword(s):  
Multivariate Analyses ◽  
Benthic Communities ◽  
Marine Species ◽  
Trophic Group ◽  
Spatial And Temporal Scales ◽  
Mediterranean Lagoons ◽  
Deposit Feeders ◽  
Spatio Temporal ◽  
Lagoon Lake ◽  
Hard Substrata

Lake Vouliagmeni (Attica, Greece) is a lagoon of great scientific interest due to its endemic fauna, widely used for recreational activities. Understanding the dynamics of this peculiar ecosystem is essential for its conservation. An ecological survey of the benthic communities was carried out, in both spatial and temporal scales. Material was collected with SCUBA diving, by taking off samples from the principal habitats of the lagoon, i.e. meadows, soft and hard substrata. The identification of the collected 61,975 living specimens revealed the presence of 12 floral and 20 faunal species. Multivariate analyses separated the sampling sites according to the four different habitats of the lagoon, whereas no temporal patterns came up. Micrograzers were the dominant trophic group, followed by deposit feeders regardless of the habitat studied. Lake Vouliagmeni is among the less diverse Mediterranean lagoons, mostly due to its isolation from the sea that hinders the entrance of marine species.

scholarly journals Evaluation on Minimum Landing Size Regulations in Turkish Marine Fisheries from Scientific Perspective

2019 ◽  
Vol 7 (sp1) ◽  
pp. 27
Author(s):  
Ozan Soykan
Keyword(s):  
Regional Differences ◽  
Fishery Management ◽  
Marine Species ◽  
Require Result ◽  
Marine Fishery ◽  
Minimum Landing Size ◽  
Fisheries Regulation ◽  
The Republic ◽  
Scientific Results ◽  
Republic Of Turkey

Crucial point of fishery management is to let the fish or other species reproduce at least once during their life. Therefore it is very important to determine the length at maturity (Lm) for given species before the first capture. Focus of this study is to determine the consistency between scientific results and minimum landing size (MLS) regulations in the marine fishery of Turkey. For this purpose, 4/1 communique on commercial fishery (2016/35) published by the Republic of Turkey Ministry of Agriculture and Forestry was investigated in order to expose the MLS of given species in Turkey. Literature survey on Lm was also conducted preferably on studies which were performed in Turkish waters or from the Mediterranean basin in order to avoid regional differences. While 86 marine species were reported to be landed in the official fishery statistics, only 49 of them were appointed with a MLS in the commercial fisheries regulation. It was determined that MLS of 27 species were below the Lm according to the selected literature, 7 of them require result on Lm, status of the 2 species couldn’t be decided due to different length types and 13 (27% of the decisions on MLS) of them were found to be in accordance with the scientific literature on Lm. This study shows that MLS regulation must be revised for most of the species in the surrounding waters of Turkey and comprehensive maturity studies are urgently needed in order to fulfill the scientific gap.

Geo-Informatics for Land Use and Biodiversity Studies

2011 ◽  
pp. 52-77
Author(s):  
P. K. Joshi ◽  
Neena Priyanka
Keyword(s):  
Land Use ◽  
Temporal Dynamics ◽  
Mitigation Measures ◽  
Conservation Strategies ◽  
Ecological Processes ◽  
Holistic Understanding ◽  
Global Positioning ◽  
Geospatial Tools ◽  
Spatio Temporal ◽  
Impact On Biodiversity

The dynamics of land use/land cover (LU/LC) is a manifestation of the cyclic correlation among the kind and magnitude of causes, impacts, responses and resulting ecological processes of the ecosystem. Thus, the holistic understanding of the complex mechanisms that control LU/LC requires synergetic adoption of measurement approaches, addressing issues, and identifying drivers of change and state of art technologies for mitigation measures. As the spatio-temporal heterogeneity of the LU/LC increases, its impact on biodiversity becomes even more difficult to anticipate. Thus, in order to understand the spatio-temporal dynamics of change in landscape and its relationship to biodiversity, it is necessary to reliably identify and quantify the indicators of change. In addition, it is also important to have better understanding of the technologies and techniques that serve as complimentary tool for land mitigation and conservation planning. Against this background, the chapter aims to synthesize LU/LC studies worldwide and their impacts on biodiversity. This chapter explores identification and analysis of key natural, socio-economic and regulatory drivers for LU/LC. Finally, it attempts to collate some LU/LC studies involving usage of geospatial tools, such as satellite remote sensing, Geographic Information System (GIS), Global Positioning System (GPS), and integrative tools, besides conventional approaches that could assist decision makers, land managers, stakeholders and researchers in better management and formulation of conservation strategies based on scientific grounds.

scholarly journals Fishery-dependent and -independent data lead to consistent estimations of essential habitats

2016 ◽  
Vol 73 (9) ◽  
pp. 2302-2310 ◽  
Author(s):  
Maria Grazia Pennino ◽  
David Conesa ◽  
Antonio López-Quílez ◽  
Facundo Muñoz ◽  
Angel Fernández ◽  
...  
Keyword(s):  
Spatial Patterns ◽  
Survey Design ◽  
Scientific Information ◽  
Marine Species ◽  
Dependent Data ◽  
Independent Data ◽  
Elasmobranch Species ◽  
Spatio Temporal ◽  
Definition Of ◽  
Spatial Locations

Abstract Species mapping is an essential tool for conservation programmes as it provides clear pictures of the distribution of marine resources. However, in fishery ecology, the amount of objective scientific information is limited and data may not always be directly comparable. Information about the distribution of marine species can be derived from two main sources: fishery-independent data (scientific surveys at sea) and fishery-dependent data (collection and sampling by observers in commercial vessels). The aim of this paper is to compare whether these two different sources produce similar, complementary, or different results. We compare them in the specific context of identifying the Essential Fish Habitats of three elasmobranch species (S. canicula, G. melastomus, and E. spinax). Similarity and prediction statistics are used to compare the two different spatial patterns obtained by applying the same Bayesian spatio-temporal modelling approach in the two sources. Results showed that the spatial patterns obtained are similar, although differences are present. In particular, models based on fishery-dependent data are better able to identify temporal relationships between the probability of presence of the species and seasonal environmental variables. In contrast, fishery-independent data better discriminate spatial locations where a species is present or absent. Besides the spatial and temporal differences of the two datasets, the consistency of habitat results highlights the inclusion in each dataset of most of the environmental envelope of each species, both in time and space. Consequently, sampling data should be adapted to each species to reasonably cover their environmental envelope, and a combination of datasets will likely provide a better habitat estimation than using each dataset independently. These findings can be useful in helping fishery managers improve definition of survey design and analyses.

scholarly journals Spatial management of Indian Ocean tropical tuna fisheries: potential and perspectives

2014 ◽  
Vol 71 (7) ◽  
pp. 1728-1749 ◽  
Author(s):  
David M. Kaplan ◽  
Emmanuel Chassot ◽  
Justin M. Amandé ◽  
Sibylle Dueri ◽  
Hervé Demarcq ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Fishery Management ◽  
Tropical Indian Ocean ◽  
Catch Per Unit Effort ◽  
Management Options ◽  
Fish Movements ◽  
Spatial Management ◽  
Spatio Temporal ◽  
Tuna Fisheries ◽  
Tropical Tuna

Abstract Effective use of spatial management in the pelagic realm presents special challenges due to high fish and fisher mobility, limited knowledge and significant governance challenges. The tropical Indian Ocean provides an ideal case study for testing our ability to apply existing data sources to assessing impacts of spatial management on tuna fisheries because of several recent controversial spatial closures. We review the scientific underpinnings of pelagic MPA effects, spatio-temporal patterns of Indian Ocean tuna catch, bycatch and fish movements, and the consequences of these for the efficacy of spatial management for Indian Ocean tropical tuna fisheries. The tropical Indian Ocean is characterized by strong environmental fluctuations, regular seasonal variability in catch, large observed tuna displacement distances, relatively uniform catch-per-unit-effort and bycatch rates over space, and high fisher mobility, all of which suggest significant variability and movement in tropical tuna fisheries that are simply not well adapted to static spatial closures. One possible exception to this overall conclusion would be a large time/area closure east of Somalia. If closed for a significant fraction of the year it could reduce purse-seine bycatch and juvenile tuna catch. Dynamic closures following fish migratory patterns are possible, but more focused information on fish movements will be needed for effective implementation. Fortunately, several recent improvements in conventional fishery management and reporting will likely enhance our ability to evaluate spatial and non-spatial management options in the near future, particularly as pertaining to bycatch species.

Spatio-temporal variations and age effect on Toxoplasma gondii seroprevalence in seals from the Canadian Arctic

Parasitology ◽  
2011 ◽  
Vol 138 (11) ◽  
pp. 1362-1368 ◽  
Author(s):  
A. SIMON ◽  
M. CHAMBELLANT ◽  
B. J. WARD ◽  
M. SIMARD ◽  
J. F. PROULX ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Serological Test ◽  
Canadian Arctic ◽  
Temporal Variations ◽  
Test Results ◽  
Source Of Infection ◽  
Food Borne ◽  
Significant Public Health ◽  
Polymerase Chain ◽  
Spatio Temporal

SUMMARYToxoplasmosis is a significant public health threat for Inuit in the Canadian Arctic. This study aimed to investigate arctic seals as a possible food-borne source of infection. Blood samples collected from 828 seals in 7 Canadian Arctic communities from 1999 to 2006 were tested for Toxoplasma gondii antibodies using a direct agglutination test. Polymerase chain reaction (PCR) was used to detect T. gondii DNA in tissues of a subsample of seals. Associations between seal age, sex, species, diet, community and year of capture, and serological test results were investigated by logistic regression. Overall seroprevalence was 10·4% (86/828). All tissues tested were negative by PCR. In ringed seals, seroprevalence was significantly higher in juveniles than in adults (odds ratio=2·44). Overall, seroprevalence varied amongst communities (P=0·0119) and by capture year (P=0·0001). Our study supports the hypothesis that consumption of raw seal meat is a significant source of infection for Inuit. This work raises many questions about the mechanism of transfer of this terrestrial parasite to the marine environment, the preponderance of infection in younger animals and the natural course of infection in seals. Further studies to address these questions are essential to fully understand the health risks for Inuit communities.

scholarly journals Discard mortality rates in the Bering Sea snow crab, Chionoecetes opilio, fishery

2015 ◽  
Vol 72 (5) ◽  
pp. 1525-1529 ◽  
Author(s):  
J. Daniel Urban
Keyword(s):  
Mortality Rate ◽  
Bering Sea ◽  
Fishery Management ◽  
Stock Assessment ◽  
Mortality Rates ◽  
Snow Crab ◽  
Commercial Fishing ◽  
Chionoecetes Opilio ◽  
Discard Mortality ◽  
The Bering Sea

Abstract Fish and invertebrates that are unintentionally captured during commercial fishing operations and then released back into the ocean suffer mortality at unknown rates, introducing uncertainty into the fishery management process. Attempts have been made to quantify discard mortality rates using reflex action mortality predictors or RAMP which use the presence or absence of a suite of reflexes to predict discard mortality. This method was applied to snow crab, Chionoecetes opilio, during the 2010–2012 fisheries in the Bering Sea. Discard mortality in the fishery is currently assumed to be 50% in stock assessment models, but that rate is not based on empirical data and is widely recognized to be in need of refinement. Over 19 000 crab were evaluated using the RAMP method. The estimated discard mortality rate was 4.5% (s.d. = 0.812), significantly below the rate used in stock assessment models. Predicted discard mortality rates from the 2010 to 2012 study were strongly correlated with the air temperature at the St Paul Island airport in the Pribilof Islands. Using this relationship, the discard mortality rate from 1991 to 2011 was estimated at 4.8% (s.d. = 1.08).

Non-parametric analysis of the spatio-temporal variability in the fatty-acid profiles among Greenland sharks

2016 ◽  
Vol 98 (3) ◽  
pp. 627-633
Author(s):  
Holly N. Steeves ◽  
Bailey Mcmeans ◽  
Chris Field ◽  
Connie Stewart ◽  
Michael T. Arts ◽  
...  
Keyword(s):  
Statistical Approach ◽  
Marine Ecosystems ◽  
Fatty Acid Profiles ◽  
Greenland Shark ◽  
Greenland Halibut ◽  
Sea Ice Extent ◽  
Poor Understanding ◽  
Spatio Temporal ◽  
Somniosus Microcephalus ◽  
Trophic Role

Shifting prey distributions due to global warming are expected to generate dramatic ecosystem-wide changes in trophic structure within Arctic marine ecosystems. Yet a relatively poor understanding of contemporary Arctic food webs makes it difficult to predict the consequences of such changes for Arctic predators. Doing so requires quantitative approaches that can track contemporary changes in predator diets through time, using accurate, well-defined methods. Here we use fatty acids (FA) to quantify differences in consumer diet using permutational multivariate analysis of variance tests that characterize spatial and temporal changes in consumer FA signatures. Specifically we explore differences in Greenland shark (Somniosus microcephalus) FA to differentiate their potential trophic role between Svalbard, Norway and Cumberland Sound, Canada. Greenland shark FA signatures revealed significant inter-annual differences, probably driven by varying seal and Greenland halibut responses to environmental conditions such as the NAO, bottom temperature, and annual sea-ice extent. Uncommon FA were also found to play an important role in driving spatial and temporal differences in Greenland shark FA profiles. Our statistical approach should facilitate quantification of changing consumer diets across a range of marine ecosystems.

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