Where do ‘Hawaiian box jellies’ come from?

Led by Angel Yanagihara, affiliate analysis professor on the UH Manoa Faculty of Ocean and Earth Science and Know-how (SOEST) and the John A. Burns Faculty of Drugs, researchers on the UH at Manoa have been fastidiously monitoring native field jellies for over 20 years. Whereas the month-to-month shoreline aggregations are understood to happen like clockwork 8-10 days after every full moon, with jelly forecasts included on the native information, mysteries have remained: Why are they showing at this explicit a part of the lunar cycle? The place do these field jellies come from and the place are they discovered the remainder of the lunar cycle? Why has this develop into a month-to-month drawback in solely the final 30 years?

With the brand new research, the group supplied in-depth solutions primarily based upon cutting-edge oceanographic approaches together with nightlong off shore vessel monitoring, pc modeling of native currents and facet scan sonar, in addition to elementary area ecology strategies and anatomical microscopy.

The senior scientist group of Yanagihara and SOEST oceanography professor Margaret McManus conceived of and started this collaborative research ten years in the past ranging from month-to-month field jelly census knowledge collected by the Yanagihara Lab from 1997 to the current.

“We discovered that the harmful month-to-month shoreline look of the Hawaiian Field Jellyfish, correlates with the precise nights of the lunar month — known as Kaloa within the Hawaiian calendar — with a crucial variety of dead nights after sundown and earlier than moonrise,” mentioned Yanagihara. “We additionally found that all the field jellies comprising the shoreline aggregation had been actively spawning.”

Based mostly on research of hundreds of beached field jellies, Yanagihara discovered that the gonads had been all replete with gametes or freshly spent — that means they had been nearshore to breed.

“The interval of the lunar cycle with a key variety of dead nights or the ‘absence of sunshine’ cues mature animals to particularly swim to the shore line to spawn,” mentioned Yanagihara. “Additional, as divers monitoring the migration within the water, we confronted a robust south easterly (Diamond Head) present that the field jellies swam efficiently perpendicular to however, we divers with tanks and massive cameras couldn’t. Their swimming velocity and energy was spectacular!”

With McManus’ oceanographic evaluation, the researchers hypothesize that jellies are within the lee of Diamond Head Crater for the remainder of the lunar cycle, benefiting from the shelter and meals supplied by the persistent eddy within the research space, which seems to be the “supply level” for the jellyfish or the place the field jellies come from.

The UH scientists are addressing problems with significance and concern to residents and vacationers alike who take pleasure in Hawai’i’s coastal waters in addition to of nice significance to different tropical islands with native populations of this similar species Alatina alata. Whereas there are over 40 species of field jellies world huge, Alatina alata is the one species that reveals this clockwork lunar spawning migration habits. The group additionally studied Alatina alata migrations in Saipan, CMNI and Puerto Rico and Key West, FL. This analysis revealed the distinctive life cycle involving particular shoreline bathymetry options which assist persistent anticyclonic eddy options in addition to the lunar set off for spawning and can permit the group to additional examine different O’ahu areas the place field jellies haven’t been noticed traditionally however have now develop into extra frequent equivalent to Pupukea and Kailua.

“This work is essential to the State by way of planning and tourism in addition to improved signage, public consciousness and dissemination of evidence-based jellyfish sting care,” mentioned Yanagihara.

Sooner or later, the group hopes to proceed these research to mannequin different offshore bay options adjoining to field jelly beaching occasions and to trace inhabitants numbers which might develop into rising public well being considerations for ocean swimmers and seashore goers. Particularly, analysis efforts are being designed to tell and predict, in addition to, to assist information insurance policies to revive meals internet steadiness to maintain field jelly numbers in verify in Hawai’i and different tropical localities the place Alatina alata additionally symbolize a priority for seashore goers.

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Supplies supplied by College of Hawaii at Manoa. Unique written by Marcie Grabowski. Notice: Content material could also be edited for fashion and size.