<div><p>At the conclusion of each haul, all bycatch was separated from the shrimp catch and sorted by species. The catch of each regulated species was weighed to the nearest tenth of a pound and individual fish were measured to the nearest centimeter. For species caught in large numbers, only the first 100 individuals caught per day were measured due to limited time between hauls in which to collect data. Because of their prevalence in the catch, measurement of silver hake, red/white hake, and both Atlantic and river herring was recorded to the nearest centimeter. Shrimp weights were estimated by counting the number of trays filled with shrimp. Each full tray weighed an estimated 100 pounds, with partial tray weight estimated based upon the proportion filled. This method of estimation was consistent with practice by fishermen and NOAA observers. The sea samplers recorded fishing gear details and grate details including bar spacing, grate angle, and grate height, width, and orientation. Operational details concerning grate deployment, retrieval, deck handling, and maintenance was also recorded, along with location, direction, and duration of each haul. Temporal comparison of bycatch was facilitated by sampling over the course of four different months at approximately the same time each month. Catch data was then compared between locations and time.</p></div>
Bycatch of regulated species and the nordmore grate in the Gulf of Maine shrimp fishery
<div><p><strong>"A Contemporary Assessment of the Bycatch of Regulated Species and the Nordmore Grate in the Northern Shrimp Fishery"</strong></p>
<p>Since April 1992, fishermen engaged in this fishery have been required to install a finfish excluder device in their trawl net, known as the Nordmore grate.<br />
(Richards & Hendrickson, 2006).</p>
<p>A data collection program was established using GMRI staff and NOAA observers to monitor and document the bycatch of regulated groundfish and non-regulated species during the 2008-2009 shrimp season. GMRI staff sampled the catch from 137 hauls (tows) over a period of 39 days (fishing trips). Initially four boats were used to collect data, one operating in the waters of northern Massachusetts, one near Boon Is., one in Saco Bay, and another in midcoast Maine. NOAA observers sampled the catch from 106 hauls over 25 fishing trips. The location of each fishing trip sampled by these observers was unknown.</p>
<p>GMRI and NOAA data indicated that the shrimp catch comprised almost 96% and 92% of total catch weight respectively. The proportion of regulated bycatch from both data sources was less than 2% of the total catch weight. In fifty-one percent of all fishing trips sampled by GMRI, regulated species bycatch averaged less than 1% of total catch weight, including all trips from midcoast Maine. In an additional thirty-three percent of fishing trips, regulated bycatch averaged between 1 – 2% of total catch weight. The bycatch of regulated species exceeded 5% of total catch weight in only 5% of hauls, and weighed no more than 55 lbs in any haul. All but one fishing trip sampled by GMRI staff had an average regulated species bycatch of less than 5% per haul. The boat operating in midcoast Maine consistently recorded the lowest proportion of regulated bycatch per haul, while the highest proportions were consistently recorded at Boon Is, particularly in January. Juvenile American plaice comprised almost 50% of regulated species bycatch sampled by GMRI staff. The effect of grate orientation was tested on one boat, but did not appear to alter grate performance.</p>
<p>The bycatch of regulated species did not exceed 5% of total catch weight in any haul sampled by NOAA observers. American plaice similarly dominated the bycatch of regulated species, but only represented 27% of the total catch of this bycatch. Grate orientation had little impact on the proportion or composition of shrimp and regulated bycatch in the total catch. (from final report abstract)</p>
<p><strong>Project goal and objectives</strong><br />
The primary goal of this project was to evaluate the bycatch of regulated groundfish species during the 2008-2009 northern shrimp season and assess the efficacy of the Nordmore grate in reducing the bycatch of regulated groundfish and non-regulated species.</p>
<p><strong>Specific project objectives were to:</strong><br />
1. Monitor and document the bycatch of regulated groundfish and non-regulated species during the 2008-2009 northern shrimp fishing season using GMRI samplers and NOAA observers.<br />
2. Compare the bycatch of regulated species during the 2008-2009 fishing season across spatial and temporal scales.<br />
3. Determine the ability of the Nordmore grate to reduce the bycatch of regulated species to 5% or less of total catch weight.<br />
4. Identify factors affecting the operational performance of the Nordmore grate and compare the catching performance of both upward and downward excluding grates.</p></div>
shrimp_nordmore_bycatch
3589
shrimp_nordmore_bycatch
2011-12-30T09:18:55-05:00
2011-12-30T09:18:55-05:00
2023-07-07T16:10:26-04:00
urn:bcodmo:dataset:3589
Bycatch of regulated species and the Nordmore grate in the Gulf of Maine shrimp fishery from Fishing Vessels NEC-SE2007-1 in the Gulf of Maine from 2009-2009 (NEC-CoopRes project)
false
Eayrs, S. (2012) Bycatch of regulated species and the Nordmore grate in the Gulf of Maine shrimp fishery from Fishing Vessels NEC-SE2007-1 in the Gulf of Maine from 2009-2009 (NEC-CoopRes project). Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version final) Version Date 2012-01-05 [if applicable, indicate subset used]. http://lod.bco-dmo.org/id/dataset/3589 [access date]
true
final
false
2012-01-05
HTML
https://www.bco-dmo.org/dataset/3589
text/html
Datapackage.json
Frictionless Data Package
https://www.bco-dmo.org/dataset/3589/datapackage.json
application/vnd.datapackage+json
PDF
https://www.bco-dmo.org/dataset/3589/Dataset_description.pdf
application/pdf
JSON-LD
https://www.bco-dmo.org/dataset/3589.json
application/ld+json
Turtle
https://www.bco-dmo.org/dataset/3589.ttl
text/turtle
RDF/XML
https://www.bco-dmo.org/dataset/3589.rdf
application/rdf+xml
ISO 19115-2 (NOAA Profile)
https://www.bco-dmo.org/dataset/3589/iso
application/xml
http://www.isotc211.org/2005/gmd-noaa
Dublin Core
https://www.bco-dmo.org/dataset/3589/dublin-core
application/xml
http://purl.org/dc/elements/1.1/
3589
http://lod.bco-dmo.org/id/dataset/3589
<http://www.opengis.net/def/crs/OGC/1.3/CRS84> POLYGON ((-70.688 42.8163, -69.0543 42.8163, -69.0543 43.9058, -70.688 43.9058, -70.688 42.8163))
JGOFS
http://www.opengis.net/def/crs/OGC/1.3/CRS84
-70.688
42.8163
-69.0543
43.9058
43.361049999998
-69.871149999997