Numerous human-caused threats are accelerating the decline of our Hawaiian coral reefs. Derelict fishing gear and trash (“marine debris”) entangles, hooks, chokes, sickens, and crushes coral plus reef dwellers. Since this debris persists in the ocean environment for many years, careful removal lessens these often-unseen impacts. Our small Turtle Team (2-12 trained people) conducted 279 surveys from Mā`alaea to Keone`ō`io, South Maui, in 2018. Marine debris was opportunistically collected during these surveys that lasted ~1-2 hours depending on ocean conditions. Everything was collected by freediving with scissors and wire cutters, and then transported on customized floats. Once ashore, items were photographed, sorted into categories and quantified. Not including the fishing line/rope, the number of other items removed per survey ranged from 0 to 366 (mean= 52.2 ± 72.1 SD). A total of 119,340 ft of fishing line/rope plus 15,198 items (2,379 pounds) were collected: 1,950 hooks, 5,820 weights (1,088 pounds), 3,123 swivels, 450 bobbers/lures, 497 leaders, 1,832 pieces of plastic trash, and 1,526 pieces of other trash. Items were either recycled, upcycled, re-used, trashed, or kept for art/educational purposes. During these 2018 surveys, our team de-hooked and/or disentangled 48 green sea turtles (Chelonia mydas). These cleanup and rescue activities show the prevalence of this issue in South Maui, which is known for its ecologically significant and beautiful coast. Statewide solutions: more community involvement, education, responsible fishing practices, and litter control plus extended producer responsibility.
This Turtle Team consisted of experienced, trained volunteers (along with the occasional group of visitors or friends) who met on a regular basis in different locations depending on availability and ocean conditions. Snorkel survey times also varied due to these conditions, but were typically 1-2 hours. The area covered also widely due to access points. The group stayed together in the water in a transect fashion (spaced out from the nearshore area to generally ~20 ft depth while no deeper than 40 ft) to cover the areas thoroughly. Caves and ledges were investigated by free-diving. The team counted individual turtles during the survey, and the total was calculated by including everyone’s counts at the end (taking into account any overlap). Photos were taken of most turtles for photo-identification purposes (each individual has unique facial and flipper scale patterns), which will eventually be collated using a computer-assisted matching program. Hawksbills were entered into the statewide photo-ID database (www.HIhawksbills.org).
Once a turtle in trouble was located, the spotter raised his/her arm into the air to communicate to the rest of the group while maintaining visual reference of the animal. Depending on the fishing gear, location, depth, behavior, and condition of the animal, the team strategized the best plan of approach. Once the turtle was caught, it was put atop our “Turtle Taxi” (a custom raft we built that stabilized the turtle while we remove the gear, or made it easier to swim the turtle to shore during serious cases). We carried our removal tools (bolt cutters, wire cutters, scissors, specialized hooks, squirt bottle, eye cloth, etc.) on a separate dive flag raft. Once the gear was removed and stored in a Ziploc bag for further analysis, the turtle was photographed for our photo-ID database, measured when possible and released immediately. If further medical treatment was needed, the National Oceanic Atmospheric Administration hotline was called (888) 256-9840.
Along the way, any “marine debris” (littered items including fishing gear) was carefully removed with scissors and wire cutters while not harming the substrate or animals. Customized pool floats were used to transport the debris to shore. The team then spread out the debris to be photographed, then sorted into categories and counted:
Weights were figured with a scale or estimated (approximate dry weight). All data were entered into a Google Form that is available online:
In addition to sea turtles, other non-target animals were also impacted, and we de-hooked and disentangled them when possible: reef fish, eels, urchins, and of course coral polyps. We have not been successful with sharks or manta rays.
The primary cause for sea turtle strandings has switched from fibropapillomatosis (a tumor-forming disease related to the herpes virus) to interactions with nearshore fishing gear. Due to the increasing human and sea turtle populations, these incidents will continue to occur. Please call the marine animal emergency hotline with any cases: (888) 256-9840.
It is known that these interactions represent a significant threat to sea turtle survival, and these observations are merely a fraction of the total cases that actually occur. We made a total of 48 “Good Samaritan” rescues around South Maui. Due to the physical resilience of sea turtles, no further medical attention was necessary for all but one of the turtles, but many conditions would’ve likely worsened if not helped. The subadult turtle that had to be flown to O`ahu for NOAA to treat had a severe case of entanglement. Its right front flipper was necrotic due to the loss of blood circulation from the tight fishing line. Since the bones were already showing as it decomposed, the whole flipper had to be amputated. We still see this turtle on the reef near where we rescued it, and will continue to document its survival.
More in-depth analyses will be done as a part of a larger study that incorporates our data from 2004 to present. In summary: hookings (small and large hooks) and entanglements (multiple types of line plus other gear) affected all size classes of sea turtles, from juveniles to adults (males and females) throughout South Maui (with the exception being at `Āhihi Kīna`u Natural Area Reserve and Keone`ō`io, where we did not find any cases this year and documented the lowest number of turtles). Not surprisingly, the majority of our rescues occurred around the old pier in North Kīhei and the Kīhei Boat Ramp, both popular fishing areas and where we focused our efforts. All rescue cases were green turtles. One adult male hawksbill #MUI44 “Psycho”, was last photographed with a large ulua hook embedded in its right front flipper with a trailing leader and swivels on 7/18/18 in Wailea, and hasn’t been reported to the statewide photo-ID catalog since:
Unlike the marine debris that arrives from around the Pacific Ocean then predominately washes ashore on the windward side of the island (unless the weather switches to Kona winds), this South Maui trash is predominantly coming directly from local coastal activities. The following table summarizes our efforts and findings within 8 South Maui regions: Keālia, North Kīhei, South Kīhei, Wailea, North Mākena, South Mākena, `Āhihi Kīna`u Natural Area Reserve (a no-fishing zone), to Keone`ō`io.
The core group of surveyors and techniques were consistent, but since the survey efforts varied, this randomized the data collection too much for statistical analyses. The total removed: 15,198 items, weighing 2,379 pounds (over one ton) consisted of primarily fishing gear. The amounts at sites varied, but this fishing gear debris type remained constant even in the `Āhihi Kīna`u Natural Area Reserve (a no-fishing zone).
The northern zone of the South Maui survey area consistently had the most debris. The South Kīhei region was surveyed the most (n=70), but the North Kīhei region had over twice as much debris removed (by weight) in only 57 surveys and consistently ranked the highest in all debris amounts except the # of bobbers/lures.
Besides the 119,340 feet of fishing line/rope, the most collected item was fishing weights: 5,820 weights weighing 1,088 pounds (nearly half of the total weight collected during this project). The second was swivels followed by hooks, plastic trash, other trash, leaders, and bobbers/lures.
The following photo collages illustrate examples of our rescues and the associated gear types:
The YouTube video is a photo compilation (by month) of most of our 2018 Maui in-water reef cleanups:
The National Oceanic and Atmospheric Administration (NOAA) promotes their “Fishing Around Seals and Turtles (FAST)” program with the assistance of the State of Hawai`i, non-governmental organizations and the community.
Prevent the Event - Tips for Fishing Around Sea Turtles
Fishermen developed the following information that may help to prevent hooking or reduce the potential for gear interactions with sea turtles when fishing.
1. Watch your gear.
Do not leave gear unattended. Stay with your gear so you can respond quickly, especially when fishing in high turtle-density areas (such as north shore beaches of most islands).
2. Check your bait often.
Checking and recasting gear helps to reduce the potential for hooking or entanglement by relocating a baited hook away from a curious turtle.
3. Retrieve and recycle old line and dispose of it responsibly.
Minimize the amount of gear and line left on the reef. Gear left on the reef can still catch and drown a turtle.
4. Use live fish bait.
Baits such as eel, octopus, squid, or dead fish may be attractive to turtles. In general, the “stinkier” your bait, the more interested turtles might be in your gear. Some fishermen believe live fish bait is less attractive to turtles and using it may result in fewer turtle interactions. This is also consistent with the biology of the species as live finfish is not part of the known green or hawksbill turtle diet.
5. Fish sunset to sunrise.
Using big game gear (for ulua) at night—from sunset to sunrise—may reduce the potential for turtle interactions. Although interactions do occur at night, some fishermen believe they have fewer interactions with turtles at night. This theory also aligns with what biologist know about sea turtle behavior, as turtles appear to feed primarily during the day and sleep at night.
6. Never feed a turtle!
Green turtles are herbivores (eat algae and seagrass), but they can become accustomed to being fed and can develop an unnatural taste for fish or squid making them more likely to take a baited hook.
7. Clean your catch away from turtles.
Keep discarded fish scraps and bait away from turtles—never throw scraps into the water or in harbors (plus, it’s illegal to discard fish scraps in harbors).
8. Report illegal gillnets!
By reporting to Hawai’i Department of Land and Natural Resources (DLNR), you are helping sea turtles, seals, fish, and fishermen: 643-DLNR (3567). See Hawai’i State fishing regulations.
The Hawaiian Islands are one of the top visitor destinations in the world, and South Maui hosts many of these visitors and our residents who are drawn to the beautiful sandy beaches, ocean recreation activities and wildlife viewing. The impacts of human activities are evident by the items that are left behind. From discarded fishing gear to a lost snorkel or littered beer bottle, none of these items belong on our coral reef. Beyond the obvious coral polyp damage plus animal injuries and deaths, it’s challenging to quantify the true effects this trash is having on the wildlife and their natural habitats, but these cleanup activities and the subsequent data collected bring to light the magnitude of the issue.
The majority of the items that were picked up were related to recreational (and possibly some commercial) nearshore fishing practices. Whether these items were intentionally left on the reef or lost accidentally, it seems there would be more of an effort to retrieve the gear before the damage to the ecosystem that supports what fishermen are trying to catch is done. Have the pono fishing ways of the past been forgotten? In addition to more outreach efforts, a fishing license program would help promote pono fishing, spread awareness of the fishing regulations plus alleviate impacts to bycatch. The sensitivity of approaching fishing-related subjects in Hawai`i is understood, so these actions need to be community-driven. The Maui Ocean Center Marine Institute has installed fishing line recycling bins around the island, so this will hopefully have a positive education and litter-prevention effect. We give the fishing line we retrieve to this program so it will be upcycled: http://mocmarineinstitute.org/turtles/
Anti-litter campaigns have been running for decades, yet society still has a littering problem. Some of the trash ends up in our environment accidentally, and our tradewinds certainly assist it getting into our ocean, but there’s no excuse for such carelessness or purposeful littering. The complicated homeless situation seemed to contribute to the trashy state of the Keālia area in our study; the economic state of our residents directly influences the state of our resources. Could Maui use more trash and recycling bins (with strong bases and lids) that actually get emptied in a timely manner along with other waste management solutions? Of course, but it shouldn’t fall upon the state and county- our community and visitors need to take an active role in the responsibility of keeping our islands and ocean clean.
The concept of extended producer responsibility, in which the creators of the products we use in our every day lives take a “cradle to grave” approach to these items, is gaining traction. If the packaging isn’t created with such harmful materials to begin with, the effects won’t be as serious when they’re littered. It goes beyond recycling since this practice has widely been publicized as no longer being economically feasible. Single-use plastics have gained the most attention lately since they’re only used briefly but are designed to out-live us. Legislative bans are being enacted locally and globally that are redirecting consumer choices and business practices. More eco-friendly alternatives exist and we applaud the individuals and businesses who are creatively utilizing them, and hope the ideas spread. Zero waste initiatives to “green” events are bringing this concept to a larger audience with the help of popular music industry and Hollywood figures.
A wide variety of stressors are threatening the health of our coral reef ecosystems. This project’s cleanup and rescue activities by a small, dedicated group of volunteers demonstrate the model example of giving back with the true spirit of aloha, and we hope these actions will resonate with more people to expand the efforts statewide. Our cleanup and rescue activities have continued, so future analyses and outreach efforts are planned with past and future data. We’re very grateful for the collaborations and support that have made this project possible.