Evidences of El Niño effects on the mullet fishery of the Patos Lagoon estuary

Vieira, João Paes; Garcia, Alexandre; Grimm, Alice M.

doi:10.1590/s1516-89132008000200025

Cited by 48 publications

(35 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Our temporal analysis based on PCNM, however, suggests that such annual cycles in abundance of marine estuarine-dependent fishes are more complex than relationships portrayed in previous studies (Chao et al 1985, Garcia & Vieira 1997, Vieira et al 1998). Instead of a regular intra-annual seasonal cycle, annual abundance of marine estuarine-dependent fishes at Patos Lagoon reveals cycles with distinct peaks that occur every 0.5 to 1.3 yr.…”

Section: Spatial Versus Temporal Dimensionscontrasting

confidence: 62%

Factoring scales of spatial and temporal variation in fish abundance in a subtropical estuary

Garcia¹,

Vieira²,

Winemiller³

et al. 2012

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

We employed a new approach linking multivariate and time series analyses to identify common versus unique spatiotemporal components of abundance variation of marine spawning fishes recruiting into a subtropical Western Atlantic estuary. Based on a 10 yr standardized monthly data set, we also investigated patterns of association for local and regional factors with annual and inter-annual variation in abundance of 5 dominant marine estuarine-dependent fishes. The total amount of variation in fish abundance explained by environmental variables was 22.4%. After factoring out shared spatiotemporal variation (0.8%), our analysis showed that temporal components had an almost 5-fold greater contribution (28.0%) than spatial components (6.4%) in explaining the variation in abundance of the 5 species. Most of the variation across the temporal scale (58.5%) was associated with annual (from 0.5 to 1.3 yr) rather than multi-year oscillations (> 2 yr). Such annual patterns were probably associated with adaptations of marine estuarine-dependent fishes for exploiting predictable pulses in seasonal productivity typically found in subtropical estuaries. In contrast, inter-annual variation in abundance occurring at a scale of 3 to 7 yr could be attributed to rainfall anomalies associated with El Niño Southern Oscillation (ENSO) events, whereas those occurring at a scale of 2 yr could be influenced by the Southern Annular Mode (SAM). Our findings corroborate the hypothesis that prevalent annual patterns of variation in the abundance of marine estuarine-dependent fishes are associated with predictable productivity pulses linked to the annual temperature regime, whereas inter-annual variations in fish abundance are associated with the influence of large-scale climatic phenomena.

show abstract

Section: Spatial Versus Temporal Dimensionscontrasting

confidence: 62%

Factoring scales of spatial and temporal variation in fish abundance in a subtropical estuary

Garcia¹,

Vieira²,

Winemiller³

et al. 2012

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…However, how dolphins will respond to the expected changes in ecosystem dynamics is still unknown. Narrowing of the single interface channel between the Patos Lagoon and the Atlantic Ocean is expected to increase outflow of river discharge (Fernandes et al, 2005), possibly acting as a barrier to the ingression of marine fish and crustacean larvae into the estuary (Vieira et al, 2008;Möller et al, 2009). As a consequence, a decrease in the abundance of marine fish assemblage in the estuary may occur, raising concerns about the local bottlenose dolphin population as they are known to feed exclusively on marine fish species 17 (Pinedo, 1982;Mehsen et al, 2005).…”

Section: Habitat Modificationmentioning

confidence: 99%

Report of the Working Group on Interactions between Humans and Tursiops truncatus in the Southwest Atlantic Ocean

Fruet

Zappes

Bisi

et al. 2017

Lat. Am. J. Aquat. Mamm.

View full text Add to dashboard Cite

In this work we compiled the available information about humans and bottlenose dolphin interactions in the Southwest Atlantic Ocean (SWAO), including issues as historical direct takes, incidental captures in fisheries, positive interactions with fisheries, interactions of dolphins with tourism and boat traffic, habitat modification or degradation, and environmental pollution. The data compiled in this review demonstrated that coastal bottlenose dolphins are under anthropogenic pressure in the SWAO. Direct take of bottlenose dolphins in the wild does not appear to be an issue of conservation concern in the SWAO. Although the species is exposed to bioaccumulation of micropollutants, it is suggested that contamination level is lower when compared to bottlenose dolphins from other continents. Coastal works can impact bottlenose dolphin behavior and habitat use in a short-term, but those seem to be reversible when works stop. Bycatch occurs throughout the species distribution and seems to be occasional in Uruguayan and Argentinean waters, where there is evidence of a historic decline in dolphin sightings. In Brazil, bycatch is apparently low in the northeast and southeast coasts, but is frequent in certain areas of southern Brazil. Studies on the subject are scarce or preliminary and a great effort is still required to understand the real impact of human activities on bottlenose dolphins in the SWAO.

show abstract

“…This affects the distribution and diversity of all estuarine-dependent species, which in turn leads to higher densities in the adjacent coastal area (Garcia et al 2003). In addition, Vieira et al (2008) suggest that during periods with less saline water intrusion into the estuary, schools of mullet that would aggregate for the reproductive migration remain dispersed. These variations in the occurrence of potential prey for bottlenose dolphins might directly affect their distribution and may explain the relationship between dolphin relative density and water temperature and salinity observed in this study.…”

Section: Effects Of Environmental Spatial and Temporal Variables On mentioning

confidence: 99%

Identifying critical areas to reduce bycatch of coastal common bottlenose dolphins Tursiops truncatus in artisanal fisheries of the subtropical western South Atlantic

Tullio¹,

Fruet²,

Secchi³

2015

Endang. Species. Res.

View full text Add to dashboard Cite

Many anthropogenic actions have an impact on coastal dolphins, with bycatch being one of the main threats. We describe the distribution patterns of common bottlenose dolphins Tursiops truncatus and periods of higher entanglement risk by the artisanal gillnet fishery in the Patos Lagoon estuary and along the adjacent coast of southern Brazil. A total of 136 dolphin groups and 187 gillnets were encountered in 69 surveys conducted between September 2006 and July 2009. Data were analyzed in relation to environmental, spatial and temporal variables using generalized additive models and a spatially adaptive local smoothing algorithm for model selection. In both areas, dolphin densities increased as distance to the estuary mouth decreased. For the estuary area, water salinity and temperature influenced dolphin distribution. Along the adjacent coast, dolphin densities were higher with distance to shore as well as in the north area during the warm period. Patterns of dolphin distribution were probably a response to the presence of preferred prey or avoidance of human-related disturbance. Kernel density showed that fishing effort was distributed along the entire surveyed area inside the estuary, while along the adjacent coast it was higher in the south compared to the north area in the warm period. The overlap between gillnets and dolphins increased considerably from the cold (33.8%) to the warm (48.6%) period. Seasonal variation in fishing effort and distribution affect the overlap and the risk of dolphin entanglement. Based on the findings of this study, a fishing exclusion area aimed at reducing bycatch was established by the Brazilian Environmental Agency.

show abstract

Evidences of El Niño effects on the mullet fishery of the Patos Lagoon estuary

Cited by 48 publications

References 14 publications

Factoring scales of spatial and temporal variation in fish abundance in a subtropical estuary

Factoring scales of spatial and temporal variation in fish abundance in a subtropical estuary

Report of the Working Group on Interactions between Humans and Tursiops truncatus in the Southwest Atlantic Ocean

Identifying critical areas to reduce bycatch of coastal common bottlenose dolphins Tursiops truncatus in artisanal fisheries of the subtropical western South Atlantic

Contact Info

Product

Resources

About