Effects of mangrove structure on fish distribution patterns and predation risks

We studied the consequences of a nonnative species introduction and changes in temperature on early mortality and recruitment of native rainbow smelt (Osmerus mordax) and nonnative alewife (Alosa pseudoharengus) in Lake Champlain using a simulation model. Distribution patterns of adults and young-of-the-year (YOY) fish were predicted using a model based on observed distribution of different age groups as a function of temperature and light profiles simulated on a daily basis. Mortality rates averaged over the growing season were calculated as a function of fish densities and overlap between adults and YOY. Survival of YOY rainbow smelt and alewife depended on which predator was most abundant. Rainbow smelt YOY mortality rates are highest when rainbow smelt adults are abundant, and alewife YOY mortality rates are highest when alewife adults are abundant, potentially allowing coexistence. August and September mortality rates were higher in the climate change scenario because of increased overlap of adults and YOY of both species. These results indicate that accounting for spatiotemporal fish distribution patterns can be important when forecasting the interacting effects of climate change and aquatic invasive species on fish recruitment.

Download Full-text

How much fish is hidden in the surface and bottom acoustic blind zones?

ICES Journal of Marine Science ◽

10.1093/icesjms/fsp136 ◽

2009 ◽

Vol 66 (6) ◽

pp. 1355-1363 ◽

Cited By ~ 21

Author(s):

Carla Scalabrin ◽

Christian Marfia ◽

Jean Boucher

Keyword(s):

Continental Shelf ◽

Autonomous Underwater Vehicle ◽

Distribution Patterns ◽

Underwater Vehicle ◽

Fish Distribution ◽

Scattering Coefficient ◽

Research Vessel ◽

Bay Of Biscay ◽

Acoustic Surveys ◽

Scientific Payload

Abstract Scalabrin, C., Marfia, C., and Boucher, J. 2009. How much fish is hidden in the surface and bottom acoustic blind zones? – ICES Journal of Marine Science, 66: 1355–1363. This paper presents results from the ALLEGRO-07 survey that was carried out from 1 to 15 September 2007 across the continental shelf in the Bay of Biscay by the RV “Thalassa”. The main objectives were to conduct experiments with a medium-sized, autonomous underwater vehicle (AUV) equipped with a fishery-acoustic scientific payload. This was needed to overcome the difficulties of sampling the surface and bottom blind zones, which are inaccessible to conventional, vessel-mounted transducers used for acoustic surveys in the Bay of Biscay. The AUV acoustic datasets from four dives were compared with those from the research vessel. The results were expressed for the nautical-area-scattering coefficient (sA) and biomass estimates. The AUV provided higher sA measurements than did the vessel. For particular environmental and fish-distribution patterns, the biomass estimated by the AUV was more than ten times that estimated by the vessel alone. The results presented indicate the magnitude of the error that may occur in acoustic surveys, if the biomass in the two blind zones is undetected.

Download Full-text

Distribution, biomass and community structure of demersal fishes of the Gulf of Carpentaria, Australia

Marine and Freshwater Research ◽

10.1071/mf9940375 ◽

1994 ◽

Vol 45 (3) ◽

pp. 375 ◽

Cited By ~ 23

Author(s):

SJM Blaber ◽

DT Brewer ◽

AN Harris

Keyword(s):

Community Structure ◽

Abiotic Factors ◽

Fish Fauna ◽

Distribution Patterns ◽

Demersal Fish ◽

Fish Distribution ◽

Sediment Type ◽

Principal Coordinates Analysis ◽

Main Site ◽

Principal Coordinates

The demersal fish fauna of the Gulf of Carpentaria was surveyed during November and December 1990. Over 300 species from 85 families were caught by trawling a systematic grid of 107 stations. The absolute mean biomass was 124.8 kg ha-1 (s.e. =44.1) for day trawls and 53.7 kg ha-1 (s.e. =6.0) for night trawls. The overall mean catch rates were 421.3 kg h-1 (s.e. = 128.5) for day trawls and 198.6 kg h-1 (s.e. =21.5) for night trawls. Biomasses were twice as high in the prawn-trawling grounds of Albatross Bay, the south-eastern gulf and Groote Eylandt as they were elsewhere in the gulf. Twenty-five species made up 75% of the biomass; the dominant families were Haemulidae, Carangidae, Leiognathidae and Nemipteridae. Community-structure and distribution patterns were analysed by numerical classification techniques and principal-coordinates analysis. These indicated six main site groups and 15 fish community groups, based on fish species occurrences and biomasses. There was a relationship between fish distribution patterns and depth of water but not other abiotic factors recorded (sediment type, salinity, temperature and turbidity).

Download Full-text

Decreasing angling catch and fish distribution patterns indicate reduced ecological integrity in Swiss rivers

SIL Proceedings 1922-2010 ◽

10.1080/03680770.2005.11902935 ◽

2006 ◽

Vol 29 (3) ◽

pp. 1519-1523

Author(s):

Marcel Droz ◽

Erich Staub ◽

Pascale A. Steiner

Keyword(s):

Ecological Integrity ◽

Distribution Patterns ◽

Fish Distribution

Download Full-text

Fish habitat modeling: from conceptual framework to functional tools

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f00-251 ◽

2001 ◽

Vol 58 (1) ◽

pp. 1-9 ◽

Cited By ~ 35

Author(s):

Daniel Boisclair

Keyword(s):

Spatial Scales ◽

Fish Habitat ◽

Fish Communities ◽

Distribution Patterns ◽

Habitat Modeling ◽

Fish Distribution ◽

Spatially Explicit ◽

Net Energy ◽

Specific Distribution ◽

Physical Attributes

Natural and anthropogenic perturbations do not always equally affect all parts of an ecosystem, and all parts of an ecosystem do not equally contribute to maintain fish communities. The increasing pressure to use natural resources and to modify habitats led to the development of approaches to identify areas of key importance for fish communities. Following these approaches, aquatic systems could be perceived as puzzles, composed of a multitude of pieces with temporally flexible physical attributes and biological roles. Such a spatially explicit framework requires models that may allow one to predict fish distribution patterns and fish net energy gain once they have adopted a specific distribution pattern. Despite the conceptual appeal of spatially explicit approaches, functional tools may be obtained only after their assumptions have been tested and their models have been validated. Efforts must be deployed to identify temporal and spatial scales at which fish distribution and abundance should be estimated and modeled. Studies on fish behaviour and the energetic consequences of these behaviours must be conducted to insure that bioenergetic criteria used to define fish habitat quality do not depend on arbitrary assumptions about fish activity costs.

Download Full-text

Image Analysis Techniques for the Study of Fish School Structure from Acoustic Survey Data

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f93-102 ◽

1993 ◽

Vol 50 (5) ◽

pp. 886-893 ◽

Cited By ~ 32

Author(s):

D. G. Reid ◽

E. J. Simmonds

Keyword(s):

Image Analysis ◽

Stock Assessment ◽

Processing System ◽

Distribution Patterns ◽

Fish Distribution ◽

School Structure ◽

Fish School ◽

Wide Range ◽

Schooling Behaviour ◽

Image Analysis Techniques

A new image analysis based processing system is described for acoustic fisheries data. In a series of a simple steps the system can identify schools and display their positions on a screen. Modifications to the identification process can be entered interactively by the operator. The system provides a wide range of parameters associated with each school, e.g., height, width, depth, shape, density, that can be entered into a database. Applications of this type of system for improving the accuracy of acoustic stock assessment, studying fish distribution patterns, and elucidating fish schooling behaviour are discussed.

Download Full-text

Diel vertical migration of fish in a Neotropical reservoir

Marine and Freshwater Research ◽

10.1071/mf16009 ◽

2017 ◽

Vol 68 (6) ◽

pp. 1070 ◽

Cited By ~ 2

Author(s):

I. G. Prado ◽

P. S. Pompeu

Keyword(s):

Power Plant ◽

Vertical Migration ◽

Diel Vertical Migration ◽

Power Plants ◽

Hydroelectric Power Plant ◽

Distribution Patterns ◽

Fish Passage ◽

Fish Distribution ◽

Hydroelectric Power ◽

Operational Variables

Vertical distribution of fish was studied immediately upstream of the Três Marias hydroelectric power plant dam from December 2010 to December 2011. Eighteen field trips were conducted for hydroacoustic sampling over a period of 24h each time, with 6-h diel sampling intervals within each of the 18 sample dates. Gill nets were used to collect information on fish species composition and length. The greater fish abundance near the surface during the night and at higher depths during the daytime over a 1-day period suggests that the behavioural phenomenon known as diel vertical migration occurs at Três Marias reservoir. Therefore, the aim of the present study was to evaluate the occurrence of diel vertical migration of fish in a Neotropical reservoir, the possible relationship with the operation of the hydroelectric power plant and the variables that may affect fish distribution in water column. Analysis of some limnological and operational variables showed that water transparency, temperature and dissolved oxygen were correlated with vertical fish distribution patterns. These results are important for proposing management measures to mitigate the effects of hydroelectric power plants on fish, such as fish passage through turbines.

Download Full-text

Environmental Determinants Influencing Fish Community Structure and Diversity in Two Distinct Seasons among Wetlands of Northern Region (Ghana)

International Journal of Ecology ◽

10.1155/2016/1598701 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 3

Author(s):

Collins Ayine Nsor ◽

Edward Adzesiwor Obodai

Keyword(s):

Community Structure ◽

Fish Community ◽

Nitrate Nitrogen ◽

Grazing Intensity ◽

Distribution Patterns ◽

Northern Region ◽

Fish Distribution ◽

Fish Diversity ◽

Fish Community Structure ◽

Dca Ordination

Fish community structure was assessed in six wetlands using cast nets, to correlate with environmental variables with diversity and distribution patterns, from 2010 to 2012. A total of 2,239 individuals belonging to 44 species and 1,938 individuals belonging to 40 species were sampled in the dry and wet seasons. Mochokid and Mormyrid families dominated fish community and constituted 14.8%, respectively, followed by Alestids (12.9%) and Chlariids (11.1%). Rarer taxons were centropomids, channids, malapteruds, and oesteoglossids and represented 1.9%, respectively. Overall, CPUE per net did not vary significantly (Tukey HSD test,p=0.27) in the dry and wet seasons. Wuntori marsh consistently showed dominance in mean monthly CPUE per net (dry =115±4.5; wet =107±7.7seasons), while Bunglung constructed wetland was the least recorded (dry =56.5±6.2; wet =58.3±4.1seasons). Fish diversity and richness differed significantly (F=0.11,p=0.03) among seasons. Environmental disturbances were season-specific and did not differ significantly (F=0.16,df=14,p=0.97) among sites. A DCA ordination explained 69% variability in fish distribution patterns, while PCA showed that 81.8% of nitrate-nitrogen, phosphate, and grazing intensity on axis 1 and conductivity, temperature, and turbidity on axis 2 influenced fish community structure. Wetland conservation must be promoted to sustain fish abundance and overall ecosystem stability.

Download Full-text