scholarly journals Freshwater turtle by-catch from angling in New Brunswick, Canada

2020 ◽  
Vol 134 (3) ◽  
pp. 222-230
Author(s):  
Constance L. Browne ◽  
S. Andrew Sullivan ◽  
Donald F. McAlpine

Turtles are among the most threatened vertebrate taxa, with populations especially vulnerable to any increase in adult mortality. By-catch from freshwater angling, as a potential cause of turtle mortality is poorly documented and little understood. Here we document cases of turtle by-catch by recreational anglers in an urban park in New Brunswick and among the wider angling communities in the province. We also consider factors that may influence rates of hooking. Although we are unable to estimate turtle hooking frequency for the provincial recreational angling community as a whole, five of 75 (~7%) anglers interviewed in the urban park reported interactions with a turtle, with most reported incidents (75%) involving hooking. Snapping Turtles (Chelydra serpentina) seem to be more prone to hooking than Eastern Painted Turtles (Chrysemys picta picta). Although we conclude that turtle hooking by recreational anglers appears to be generally uncommon in New Brunswick, even apparently low by-catch rates may be sufficient to lead to population declines at heavily fished sites. The collection of additional data on turtle by-catch in the recreational fishery in Canada is warranted. 

2017 ◽  
Vol 98 (8) ◽  
pp. 2099-2111
Author(s):  
Fikret Öndes ◽  
Michel J. Kaiser ◽  
Lee G. Murray

Baited trap or pot fisheries are considered to have relatively few wider ecosystem effects on the marine environment, particularly when compared with towed mobile fishing gear. However, this assumption is rarely tested in the field. This study aimed to determine the composition of non-target species that occur in crustacean pots and to assess spatial and temporal differences in catches in the waters around the Isle of Man, Irish Sea. The data were collected using fishery independent surveys and a questionnaire study. Based on fishery independent surveys, a total of five taxonomic groups and 43 species occurred as by-catch. The dominant by-catch species was velvet crab Necora puber. The by-catch per unit effort (BPUE) for all of the non-target species was low particularly in comparison to towed bottom gear fisheries around the Isle of Man. BPUE of species composition varied considerably between different locations around the Isle of Man. The results of both the fishery independent and questionnaire data suggested that the by-catch rates varied with season with peak BPUE occurring in spring which then declined into autumn and winter. By-catch composition did not decrease significantly with an increasing target species catch. Overall, by-catch was low relative to target species catch which may be partially attributable to the use of escape panels in pot fisheries in the Isle of Man.


1993 ◽  
Vol 44 (4) ◽  
pp. 577 ◽  
Author(s):  
H Williams ◽  
G Pullen

The seasonal, lunar and diurnal changes in schooling of jack mackerel were examined using log-book information collected from an industrial fishery off the east coast of Tasmania between 1985 and 1989. School size increased significantly from spring to autumn. The ratio between surface and subsurface schools encountered by the fishery also changed seasonally. Surface schools predominate during summer, whereas subsurface schools become more frequent during autumn. The fishery was predominantly a day fishery and no lunar effects on catch rates or fishing intensity were detected. Catches mainly comprised jack mackerel, although redbait (Emmelichthys nitidus Richardson) and blue mackerel (Scomber australasicus Cuvier) were a significant by-catch. In summer, schools were almost exclusively composed of jack mackerel, but in other seasons mixed schools were found. Data presented, together with evidence from other sources, suggest that the availability of schools to the fishery may be closely related to the availability of feed.


1998 ◽  
Vol 49 (7) ◽  
pp. 653 ◽  
Author(s):  
S. F. J. Dudley ◽  
R. C. Haestier ◽  
K. R. Cox ◽  
M. Murray

Protective gill-nets (shark nets) have been successful in reducing the frequency of shark attacks on the coast of KwaZulu-Natal (KZN), South Africa, since 1952. This is achieved primarily through a local reduction in numbers of large sharks. Yet the nets are non-selective in terms of shark species caught and take a by-catch of dolphins, sea turtles, batoids and teleosts. Baited lines, or drumlines, as used in the Queensland shark control programme, were tested as possible alternatives to gill-nets. They demonstrated greater species selectivity for sharks and also a reduced by-catch of non-shark animals. The shark catch included the three species responsible for most shark attacks on the KZN coast, Carcharhinus leucas, Galeocerdo cuvier and Carcharodon carcharias. The probability of the bait being scavenged, or a shark being caught, was modelled in relation to a number of physical environmental factors. Although there was insufficient variability in the effort data for a quantitative comparison of catch rates between nets and drumlines, the results suggested that an optimal solution may be to deploy a combination of nets and drumlines.


1999 ◽  
Vol 56 (1) ◽  
pp. 113-123 ◽  
Author(s):  
Edward A Trippel ◽  
Michael B Strong ◽  
John M Terhune ◽  
Jeremy D Conway

Demersal gill nets equipped with acoustic alarms reduced harbour porpoise (Phocoena phocoena) by-catch rates by 77% over those without alarms in the Swallowtail area of the lower Bay of Fundy during field testing in August 1996 (68% reduction) and 1997 (85% reduction) (both years combined, three harbour porpoises in 249 alarmed nets versus 14 harbour porpoises in 267 nonalarmed nets). The alarms spaced 100 m apart along the net floatline produced a 0.3-s pulse at 10-12 kHz every 4 s at a level of 133-145 dB re 1 µPa at 1 m. In conditions of no rain and low wind (Sea State 0-2) the alarms were presumed to be clearly audible to harbour porpoises at ranges of 0.1-0.6 km. Catch rates of Atlantic herring (Clupea harengus), Atlantic cod (Gadus morhua), and pollock (Pollachius virens) were not significantly different in alarmed and nonalarmed nets (except in one season when pollock were caught in lower numbers in alarmed nets). Harbour porpoise by-catch and herring movements may be linked. During years of low herring abundance, we also observed low harbour porpoise entanglement rates.


2006 ◽  
Vol 120 (4) ◽  
pp. 438 ◽  
Author(s):  
A.-S. Bertrand ◽  
S. Kenn ◽  
D. Gallant ◽  
E. Tremblay ◽  
L. Vasseur ◽  
...  

For the last 40 years, the presence of Cougars (Puma concolor) in eastern Canada has been highly controversial. The purpose of this study was to collect physical evidence of Cougars using a passive detection method. Baited hair-traps combined with camera-traps were installed in New Brunswick and Nova Scotia, Canada. DNA analyses on two hair samples confirmed that the species was present in southern New Brunswick in 2003. A footprint photographed after an observation of a Cougar by reliable observers was examined by experts and was consistent with a Cougar footprint. Additional data are required to determine the status of Cougars in the northeastern part of its historical range.


2000 ◽  
Vol 57 (10) ◽  
pp. 2010-2021 ◽  
Author(s):  
Sandra L Diamond ◽  
Lindsay G Cowell ◽  
Larry B Crowder

We used stage-within-age based matrix models of Atlantic croaker (Micropogonias undulatus) in the Gulf of Mexico and the South and Mid-Atlantic bights to explore the population-level impacts of shrimp trawl bycatch on estuarine-dependent fishes and to investigate tradeoffs between directed adult fisheries and bycatch mortality. The Gulf model reflected a rapidly declining population, while the Atlantic population showed a modest decline. Elasticity analyses indicated that both populations were more sensitive to the summed survival of adults than first-year survival, particularly in the Gulf. Contrary to our expectations, bycatch mortality on late juveniles was not the most important factor affecting either population of Atlantic croaker, and this result was robust to uncertainty in both adult and late juvenile mortality estimates. Both populations were most sensitive to ocean larva mortality, followed by mortality of estuary larvae and adults in the Gulf and of early juveniles and adults in the Atlantic. Nonetheless, bycatch mortality did have a large negative impact on population growth rates, and reducing late juvenile or adult mortality by about 35% in the Gulf or 5% in the Atlantic should reverse population declines. Bycatch reduction devices currently in use can achieve these desired reductions.


PLoS ONE ◽  
2015 ◽  
Vol 10 (7) ◽  
pp. e0131660 ◽  
Author(s):  
David W. Johnston ◽  
Jaime Frungillo ◽  
Ainsley Smith ◽  
Katie Moore ◽  
Brian Sharp ◽  
...  

1982 ◽  
Vol 60 (10) ◽  
pp. 2239-2244 ◽  
Author(s):  
Robert G. Randall

Postemergent downstream dispersal of Atlantic salmon fry (Salmo salar) was monitored using drift samplers during spring 1978 in two Miramichi River, N.B., tributaries. Catch rates of salmon fry peaked during the 2nd and 3rd weeks of June in both streams, coinciding with peak emergence of the salmon from the gravel. Very few trout fry (Salvelinus fontinalis) were captured in the drift nets, but electrofishing results indicated trout emergence preceded salmon by about 3 weeks.The earlier emergence of the trout gave them an early growth advantage over the salmon, so that trout fry were usually larger than salmon fry inhabiting the same stream areas. Early growth rates of both salmon and trout were quite varied among four stream sites during 2 years when growth was monitored; growth differences were discussed in relation to stream temperatures and density-dependent growth. Salmon fry were more abundant than trout fry at most sites in both years.


2018 ◽  
Vol 82 (S1) ◽  
pp. 131 ◽  
Author(s):  
Paolo Sartor ◽  
Daniel Li Veli ◽  
Francesco De Carlo ◽  
Alessandro Ligas ◽  
Andrea Massaro ◽  
...  

This study aimed to test the effectiveness of a “guarding net”, a device placed at the bottom of a trammel net, for reducing unwanted catches in the caramote prawn trammel net fishery of the Ligurian Sea. This specialized and profitable fishery is affected by unwanted catches that generate high discard rates and damage to the nets, with environmental impacts and costs for fishermen. The experimental study consisted in comparing the catches of a standard trammel net (STN) with those of two “experimental” trammel nets, e.g. STNs provided with a guarding net of 19 cm (TGN20) and 24 cm height (TGN25), respectively. The guarding net, a strip of gillnet placed at the bottom of the net, can be considered a by-catch reducer device (BRD). Some fishermen of the investigated fishery have been using this device for several years. The results of the 15 experimental fishing trials performed from June to July 2016 indicate that the guarding nets significantly reduce discards (e.g. crabs and other invertebrates); the biomass of the unwanted species caught was 75% lower than that produced by the STN. The catch rates of the target species obtained with TGN20 and TGN25 were also significantly lower than those of the STN, though of a lesser amount. Nonetheless, this economic loss can be compensated by the decrease in sorting time and material and labour costs that can be achieved using the guarding net.


Sign in / Sign up

Export Citation Format

Share Document