2015 Field Season
The 2015 field season began on May 8, but due to high water levels from the harsh winter and large amounts of snow, the elver traps could not be put into the river until May 13, and weren't up and running until May 18. Biological sampling began May 8, as the Atlantic elver fishers left a sample of about 100 elvers from their catch for Coastal Action employees to sample while waiting for the water levels to lower.
The 2015 field season is ongoing.
2014 Field Season
The field season began in April when the elver traps were set up in East River, Chester. The traps were checked daily and biological sampling was performed each Monday, Wednesday, and Friday, just as in previous years. The traps were removed from the river in late June. The total number of elvers caught was 1 733 452, and 1620 juveniles.
Eel pots were deployed in Oakland Lake in July. Following protocol from previous years, each eel captured was scanned for the presence of a PIT tag and injected with one if absent, and measured for weight and length then released. The total number of eels caught in Oakland Lake was 141, with 95 being recaptures from previous years.
The instream trap was placed in Oakland Stream in late August. The trap was taken out of the stream at the end of October. The total number of silver eel caught was 513, while 10 of these eels had a PIT tag from the Oakland Lake portion of the study. 15 of the captured eels were yellow.
Two traps were put in East River, Chester in late August to capture silver eel leaving the river. This was the first year that this mark-recapture study was incorporated into the American eel project. Trap locations were changed numerous times to determine the most suitable sites. A recapture site was set up near the mouth of the river, while a mark site was placed about 1 km upstream. In total, the upstream sites caught 1977 eel, while only 141 were marked. The downstream sites caught 477 eel. Of these, only one eel had evidence of being a recapture but no tag was present.
2013 Field Season
In the fifth year of the American eel study, the Oakland Lake portion began on June 26 and ended August 2. A total number of 126 eel were captured; 45 were PIT tagged, 59 were recaptures, and 22 were released without any mark due to some being injured as well as an unavailability of PIT tags. The average length and weight of eel captured was 185.165cm and 42.76g, respectively. Compared to previous years, 2013 was the lowest catch since the study began.
The Oakland in-stream trap was operational from August 16 to November 4. The trap was installed about a month earlier than usual, in hopes of catching a larger number of migrating eel. The trap was in place for a total of 81 days. A total of 559 migrating eel were captured, 17 of which had previously been PIT tagged in the lake. Assuming silver eel larger than 45 centimeters are female, 146 female and 380 male silver eel were captured. The remaining 33 eel were still considered to be in the yellow eel phase.
2012 Field Season
The 2012 Oakland Lake mark-recapture study began on June 15th and ended on September 6th. Along with American eel length and weight, by-catch data were recorded. The total number of eel caught during the 2012 season were 156. Of these 156 eel, 55 were recaptures. The overall average length and weight for the eels caught in Oakland Lake was 178g and 43cm.
The Oakland stream trap was installed on September 10. On September 11, the catch totaled 168 eel, which was the highest daily catch for the study season. The last eel was caught on October 18th and the trap was removed on October 24th. The total number of eels caught during the 2012 in-stream trap study amounted to 405 eels with 13 recaptures. This is the highest catch since the study began in 2009. One of the recaptured eels had been acoustic tagged as well as PIT tagged.
2011 Field Season
The Bluenose Coastal Action Foundation conducted an American eel habitat assessment study on Oakland Lake, Nova Scotia. By-catch data were recorded to provide an insight as to what types of fish inhabit the lake other than American eel. This year, an elver abundance study for Oakland Stream was operational from April 20 to June 6. An American eel habitat preference study for Oakland Lake began June 6 and was completed September 29. The study began with 29 eel pots and 16 additional pots were deployed June 29. Eels were scanned for previously injected tags, anesthetised using clove oil, and then measured for length and weight. Untagged eels were marked using a PIT tag. During the 2011 field season, a total of 374 eels were caught in the lake, with 149 of them being recaptures.
The 2011 season also saw Coastal Action partner with Acadia University to develop two new Honours projects based on the American eel. Jon Cottreau looked at habitat mapping within Oakland Lake and Andy Muise looked at habitat use by eel within the East River, Chester watershed.
2010 Field Season
Coastal Action conducted an American eel habitat assessment study in Oakland Lake and the Mahone Bay estuary. Data on abundance and physical characteristics was also collected from a stream that runs from Oakland Lake into the estuary itself. An elver abundance study for Oakland Stream was operational from April 23 to June 30. The eel study for Oakland Lake began May 26 and was completed on August 24. The study began with 29 eel pots. Eels caught that required sampling were anesthetised using clove oil then measured for length and weight. Untagged eels were marked using a PIT tag. If recapture occurred, the tag number was traced back to data on the individual eel. Over the 2010 season, a total of 176 eels were caught in the lake with 67 of them being recaptures. This procedure was duplicated in the Mahone Bay estuary and yielded a capture of only two eels total.
2009 Field Season
The Bluenose Coastal Action Foundation conducted an American eel habitat assessment study on Oakland Lake and the Mahone Bay estuary. Also, data on abundance and physical characteristics was collected from a stream that runs from Oakland Lake into the estuary itself. The study began on July 13, and was completed on October 28. The objective of this study was to determine the habitat conditions American eel prefer based on a standardized habitat assessment. Though the results from the study were specific to the Mahone Bay area, they will be looked at in a more general context and related to the entire Scotia Fundy area of the Atlantic Region.
A total of 29 traps were placed around Oakland Lake based in differing habitats. The bait used for the project was frozen herring. The trap placements were chosen roughly on the slope, amount of vegetation, lake-bottom composition, shoreline composition, and depth. The goal was to ensure that the traps were in a variety of different habitats around the lake. Eels caught were processed by being anesthetized in clove oil and then measured for lengths and weights. The eels were marked using a PIT tag. If caught again, during the current study or in another year’s survey, the tag number can be related back to the data collected on the individual. A total of 145 eel were caught in the lake, with 38 of them being recaptures.
This procedure was duplicated in the Mahone Bay estuary, with traps being placed in a variety of areas, using the same protocols as were employed in the lake study. The estuary study only yielded a capture of 5 eels in total.
In September, the instream flume trap was placed in Oakland Stream. This trap was checked on a daily basis and any eels caught were scooped out of the cage using a trout net. They were processed using the same procedures as those caught in Oakland Lake and the Mahone Bay estuary. The trap caught a total of 219 eels, with only 2 being recaptures from the initial lake study. This part of the study concluded in the end of October.