Posted on November 4th, 2014

Back to School – Lobster Traps

Last summer I stayed with friends in Portland, Oregon. They were avid campers so each weekend we would go somewhere new; sometimes it would be car-camping so we could bring coolers full of beer or the canoe, and sometimes we backpacked deep into the thick of it with everything we needed on our backs. On one of the former trips, my friend mentioned that he would be bringing his crab traps to catch crawfish. We spent the weekend dropping pods throughout Timothy Lake on Mt. Hood, going out periodically to reap our bounty and looking forward to the return home to do some southern style cooking with northwestern mud bugs. Well, on our last run to scoop the traps, we came across a few items we didn’t intend to catch, namely an old reel and someone else’s pod. Clearly lost and forgotten items, respectively, we brought them with us and didn’t think much of it.

study_areaThe study area within BNP with debris removal site locations indicated.
hot_spotsA progression of hot spot maps which consider benthic habitats, depth, frequency of debris and seagrass locations.

Researchers at the University of Miami (affectionately known as “The U”) set out on a study to look at the dispersal of lobster trap debris in Biscayne National Park (BNP), Florida. They hoped to assess removal efficiency and see how GIS technology could be employed for the sake of trappers’ purse strings and the health of our waters. Through a well-developed literature review, the authors noted that lost or discarded fishing gear can have many negative effects on our waters and marine-life. Not only can these items ensnare marine-life, but their very presence can be detrimental to the structure of ecosystem interactions, as well as have harmful impacts on delicate life-forms such as reefs.

The study was based on existing data compiled over 5 years that tracked debris removal efforts in BNP. In contrast to most nationally protected parks, state law in Florida allows fishing and trapping in the sheltered waterways. Through the use of existing data, accompanied by newly collected data, the researchers created maps of “hot-spots” where trap debris was most likely to accumulate and thus potentially impact marine-life quality.

The new spatial data used in this research was collected by two contractors working in the study area for four weeks collecting debris. One contractor towed divers near the surface, and the other towed divers near the seafloor. The latter method of debris designation and data collection put divers in better contact with accumulated rubbish, and as you would assume, allowed for this contractor’s method of recovery to be more fruitful at nearly two times the efficiency of the surface trawl.

In the researchers’ analysis of existing data, they hypothesized that the amount of debris would be highest during the first attempts at garbage removal from the waterways. However, this did not appear to be the case. It appeared that fishers and trappers were still careless, or unlucky, in regards to their fishing equipment throughout the 5-year study period.

The research team, at the time of the submission for publication, was still in the process of improving and tweaking their spatial model. Their suggestions for improved of debris tracking and recovery included mandatory documentation of the number of traps deployed, trap soak periods and dispersal of traps in relation to preferred lobster habitat locations. The reef hot spot map they created was intended to enhance cleanup efficiency in future efforts, as well as to minimize the impact (and its duration) of lost, abandoned or forgotten traps on marine-life.

Justin Harmon
Staff Writer

This entry was posted in The Geospatial Times and tagged , , , by Katie. Bookmark the permalink.

Leave a Reply

Your email address will not be published. Required fields are marked *

Time limit is exhausted. Please reload CAPTCHA.

This site uses Akismet to reduce spam. Learn how your comment data is processed.

    The Geospatial Times Archive