Bioblitzing for Fish on the Grand River

Approximately 24 Hours prior the start of the 6th International Barcode of Life Conference, a team of over 100 international scientists set off to survey as many species at the rare Charitable Research Reserve. Participants from 36 institutions and over 17 countries volunteered their time assist with collecting, sorting, identifying and plating. This bioblitz was unique due to the smaller scale and duration which was 12 hours instead of 24 hours, none the less, the results were impressive.

The fish surveying team consisted of seven individuals. Equipped with angling gear, a seine net, cast net, and a D-frame dip net, we set off to sample Site 1 on the Grand River (Cambridge, Ontario). The site was an ideal fish sampling location due to the highly diverse habitats present in the area, which tends to correlate with the overall fish diversity. Of the habitats present in the river, the rocky (gravel and boulder), sandy, and silt bottom dominated. Heavy macrophyte growth was notable along the shoreline and the middle of the river in areas of persistent flow. We tactically targeted the fish in these habitats in order to increase the diversity of our catch. After several trial runs with the seine and cast net we got the technique down and gathered over 50 fish in less than 2 hours. The next task was to identify all of the fish caught; we placed them into larger buckets with freshwater to ensure they will have enough oxygen to be able to last the whole identification process.

Map of the rare Charitable Research Reserve collecting sites for the 2015 Bioblitz
Map of the rare Charitable Research Reserve collecting sites for the 2015 Bioblitz

There were a few specimens that were very difficult to identify. We caught several fish from the family Cyprinidae, this family is notoriously hard to identify and requires a sharp and trained eye to distinguish between subtle characteristics of the individuals within the family. Our greatest identification challenge were a few specimens from the Cyprinid family, due to so many shared similar characteristics we weren’t able to determine if we had caught a Common Shiner (Luxilus cornutus), Striped Shiner (Luxilus chrysocephalus), or a hybrid of the two. Common Shiners and Striped Shiners frequently hybridize, adding to the challenge of being able to accurately identify the specimens. Due to the uncertainty, we are waiting on a confirmation from an expert.

Counting anterior dorso-lateral scales of a specimen from the Cyprinid family
Counting anterior dorso-lateral scales of a specimen from the Cyprinid family

Here are the fish species list from the blitz:

Confirmed

White Sucker (Catostomus commersonii)

Largemouth Bass (Micropterus samoides)

Pumpkinseed (Lepomis gibbosus)

Rock Bass (Ambloplites rupestris)

Smallmouth Bass (Micropterus dolomieu)

Blackside Darter ( Percina maculate)

Johnny Darter (Etheostoma nigrum)

Yellow Perch (Perca flavescens)

New sightings (not on check list given by rare)

River chub (Nocomis micropogon)

Greenside Darter (Etheostoma blennioides)

Brook stickleback (Culaea inconstans)

Waiting for confirmation from taxonomic expert

Common Shiner (Luxilus cornutus)

Striped Shiner (Luxilus chrysocephalus)

Blackchin Shiner (Notropis heterodon)

A notable collecting limitation was the type of seine net we utilized, which was very small (3 m) and lacked a ‘collecting pouch’ that funnels all the fish into the pouch with the assistance of the current instead of letting the fish to escape out the sides. Due to this limitation, the number of fish collected was lower and we weren’t able to collect the elusive catfish (Ictaluridae) – they successfully evaded all our nets that day. Since were unable to catch it and identify it under close inspection, we could not include it to our total species count.

The predominant invasive species which encountered was the rusty crayfish (Orconectes rusticus), this aggressive and hardy species of crayfish outcompetes all of the native crayfish which resulted rusty crayfish’s population numbers to explode all over the northern US and Canada over the past 50 years (Image 3). Here is an informative website about the rusty crayfish in Ontario and how to identify them (http://www.invadingspecies.com/invaders/invertebrates/rusty-crayfish/).

The rusty crayfish (Orconectes rusticus)
The rusty crayfish (Orconectes rusticus)

The results from the rare Bioblitz were impressive; including an initial four month survey of the area; a total of 1,100 species of animals, plants, fungi and lichens with 181 species of spiders were added to the nature reserve’s inventory. This increased the rare Charitable Research Reserve’s inventory of cataloged species by 49 percent. The results of this survey can be found here. You can also watch a short video of the rare Bioblitz here.

  • Adrian

 

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