(c) Deron Verbeck
We caught up with Kenton Geer recently to get his perspectives on his shark tagging experiences while participating in the Hawaii Community Tagging Program (HCTP). Kenton is a passionate, life-long fisherman with a tangible connection to the ocean. After 26 years of fishing, beginning when he was a teenager, Kenton has worked as a commercial longliner, a charter fisherman, and even a bluewater spearfisher. But more recently he is known for bringing in high quality ahi from ‘the mountain’ or Cross Seamount—an underwater mountain,130 miles south and west from the Kona coast and rising 14,993 feet from the seafloor. Since 2005 Kenton has been fishing at Cross Seamount, and with a transit time of 18 hours or more, Kenton ends up spending more days at-sea than on land. Typically he is offshore around 200 days a year, but has had years with up to 300 days at-sea!
When fishing at Cross Seamount, Kenton targets tuna using several fishing methods. He sets shortlines which are short longlines about a mile long and also uses handlines during the day and at night. During the day, he fishes a style called palu ahi, where he slowly drifts over tuna aggregations while throwing bait in the water and jigging with baited hooks. At night, he fishes ika-shibi style—bait is thrown on the water while fishing with baited handlines set at different depths and an old military parachute is deployed that works as a sea anchor to allow him to drift along a current line.
With all this time at Cross Seamount, he has seen day-to-day, seasonal, and yearly changes to the catch composition and the movements and behavior of the pelagic species (fish, birds, marine mammals) that he encounters out there. Notably he observed differences in the sightings of false killer whales and Oceanic whitetips when fishery closures occurred from 2018 through 2020 to commercial longline fishing in the Southern Exclusion Zone—a management area created south of the Hawaiian Islands that closes to longline fishing when False killer whale bycatch reaches a certain level. When the area was closed, he saw an absence of False killer whales, but once reopened the False killer whales returned. He speculates, these whales may have learned to depredate the catch and bait from the longliners when they are in the area and are actually following the vessels.
He also noticed more Oceanic whitetip sharks in the area during the closure. Typically, he only sees a couple Oceanic whitetips a week, but during the closure he observed a couple sharks a day. Kenton also relayed to us that when he talked with some of the old timers that used to fish on the ‘mountain’ they also remembered more Oceanic whitetip sharks around Cross Seamount, to the point where they were eating their catch. However, Kenton doesn’t consider shark interactions to be a nuisance, instead he has learned how to fish alongside them. Now if sharks are becoming a problem he picks up his gear, moves about one mile away, and finds a new pile of ahi, with about a 95% success rate of avoiding shark interactions at his new spot.
Kenton has also become one of our more prolific shark taggers. To date Kenton has tagged over 20 pelagic sharks (Oceanic whitetip, Blue, Silky, and Bigeye thresher sharks) with a combination of tag types to help us understand habitat use and movement behavior. With all of this tagging he has found that after he tags a shark, they appear annoyed, and leave the area. This observation got him thinking that tagging could be an effective shark deterrent, or some other similar action could be performed that places a biodegradable “tag” on the animal so that no plastic was left in the ocean (our tags are very expensive ~$4000 and made of syntactic foam and electronic hardware). He suggested building biodegradable “tags” with galvanic links for problem sharks. Which is actually something that we had previously tried with a few of our fishers. We have sourced galvanic links that break after 2-4 hours and now we just need to find appropriate biodegradable materials (hint hint to all of our resourceful water people)!!
Having spent so much of his time on the water Kenton is starting to connect the dots between cause and effect. Over the last ten years, he has witnessed declines in Mahimahi catch and feels it is related to an increase in plastics in the ocean. As a thrifty fisherman, he re-uses his bait, so he guts each Mahimahi caught. This has revealed that these fish are consuming a lot of plastic. This may be a particular concern for Mahimahi, because they tend to hit the surface when feeding or eating along debris lines. With such a strong connection to the ocean, Kenton feels he knows what is right and wrong, and doing what is right for the environment and for the fish populations that sustain him is more important than making a buck. He believes we should set the example here in U.S. waters for foreign fleets to follow. Particularly when it comes to fishing shared resources and conserving the striped marlin population that has plummeted in the Pacific.
It is clear that Kenton wants to preserve fish populations and that he feels that sharks are integral to a healthy ocean ecosystem. When I asked him the most interesting thing he has observed on the water, he excitedly told me the story of when he saw a 150 lb marlin surface followed by a Great white exploding out of the water and annihilating this marlin in one big bite! He also shared with me a second fish “tail” of when he witnessed a Thresher shark using its tail to slap Opelu on the surface in a bait ball. These kinds of direct observations of fish behavior are so valuable and informative for us. We are grateful to Kenton and our participating fishers for sharing their stories, helping us make sense of the data we are collecting, bridging communication, and collaborating in problem solving to improve fisheries sustainability.