Meeting Abstract
The invasive Green crab, Carcinus maenas, and Asian shore crab, Hemigrapsus sanguinaeus, have rapidly increased their populations, particularly on the coast of Maine, leading to a significant and detrimental effect on coastal intertidal areas. We have monitored both populations in Biddeford Pool over 6 years. Our data show that both species are established in the area and have reproductive seasons that overlap, but peak about 4 weeks apart during early summer. In addition, green crabs were shown to be egg bearing in the winter months. To determine if their eggs are viable year-round, and produce viable larvae, we designed a remote-controlled boat with an attached plankton suction device that can be deployed in shallow and deep waters. The plankton suction device is comprised of a 60 cm 4 inch acrylic pipe with a BlueRobotics T100 thruster, 200 µm plankton net, and a General Oceanics mechanical flowmeter. Samples collected with the RC boat-driven plankton sucker were analyzed using a FlowCam particle imaging system. Due to a lack of crab larvae abundance in the FlowCam-analyzed samples, we designed an environmental DNA (eDNA) protocol to detect the presence of green crabs in the water column. Focusing on the COI1 gene of green crabs and other crustaceans in Maine, such as the Asian shore crab, the Jonah crab, Cancer irroratus, the rock crab, Cancer borealis, and the American lobster, Homarus americanus, we designed specific quantitative PCR primers and probes for green crabs. We then set up a filtration system to separate isolate eDNA from the plankton tows using the Qiagen DNeasy kit. We are correlating FlowCam and eDNA analyses to test which method allows for a reliable and economically viable monitoring program for marine invasive species. Supported by NSF grants MRI-1624984 and IUSE-1431955 to M.F.
