What seaweed can inform us about the environment in Hawaii


What to listen to extra? Subscribe to ‘Steaming the Tide’ or take a look at Civil Beat’s different podcasts.

Seaweed, macroalgae, kelp – there are a lot of totally different names for sea vegetation, however in Hawaii, it’s limu.

Earlier than western contact, limu had been an vital a part of Hawaiian tradition and way of life. Generally present in meals dishes, it was additionally used as drugs and in cultural practices similar to making lei or dyeing garments. One selection, limu artwork, was usually a part of hooponopono practices – reconciliation ceremonies – with members consuming or holding the plant.

As the bottom of the marine meals chain, the limu additionally performs an vital position in intertidal ecosystems because it supplies meals and shelter for small invertebrates and herbivores.

Limu Valley Ito Crustacean Limu Kohu
Limu professional Wally Ito factors to a small crustacean that was discovered on this piece of Limu Koahu. Ku’u Kouano/Civil Beat/2022

However over the previous few many years, the native limu and its myriad varieties have confronted many challenges in Hawaiian waters. Invasive algae species and local weather change, in addition to land improvement and groundwater contamination, have created a lethal mixture for limu.

Veronica Gibson, a doctoral scholar on the College of Hawaii Manoa, has been learning LIMU for greater than 10 years and even she says we’re originally of understanding it. Nevertheless, it has change into clear what position persons are enjoying in shaping its future.

limu veronica gibson diving
Veronica Gibson grew up in Kona, the place her appreciation for Limu started along with her love for the ocean. She now research groundwater results on limu as a doctoral candidate on the College of Hawaii Manoa. Elizabeth Sides

“We as people are ecosystem engineers who resolve what turns into invasive and the way we management our results on these ecosystems,” she stated.

Gibson believes that if extra folks knew what native ecosystems regarded like, they might be capable to report uncommon modifications.

“We wish to handle this for a lot of generations sooner or later, in order that they’ll get pleasure from this stuff and never lose the biodiversity, productiveness and tradition related to these methods,” she stated.

Coping with the issue is difficult. But it surely begins with understanding what’s offensive and why.

The Division of Lands and Pure Assets has a complete record of invasive algae species in Hawaii. Identified for capturing native species, muck weed, hook weed and even one known as “smothering seaweed” make a minimize.

Usually, invasive macroalgae are outlined as international species that dominate reefs and inhibit the expansion of different plant, invertebrate and fish populations. However even the native limu can overtake the coral and the launched limu can be taught to adapt to its setting.

Hawaii Grown

“I consider ‘introducing’ or ‘alien’ as a place,” stated Ryan Okano, program supervisor for the DLNR Division of Aquatic Assets. “Aggressive, to me, is a trait that may be expressed by a species launched into unnatural situations.”

Gracilaria salicorniae, often called the gorilla ogo, was initially delivered to Hawaii as a meals. The small and stocky species was launched from Hilo to Oahu and though some use it for pork or poke, the availability outweighed the demand.

Gibson has witnessed the unfold of the gorilla Ogo within the waters of Oahu over the previous 12 years, even taking part within the Ogo cleanup in Waikiki, and believes it stands as a cautionary story. It’s attainable

“Watch out with what you introduce as a result of it is actually arduous to foretell what is going to occur,” Gibson stated.

On account of asexual copy by means of fragmentation, or fragmentation, the gorilla ogo rapidly took over the east and north coasts, the place its native counterpart, the Limu manoa, thrived.

“It modifications the ecosystem with its abundance, however this isn’t fascinating,” Gibson stated.

Limu Valley Ito Malia Heimuli Vanula Beach Park Eva Beach
Wally Ito collects specimens of the native limu at Van’ula Seashore Park. He would later protect them in a binder to indicate and educate Hawaiian college students about limu. Ku’u Kouano/Civil Beat/2022

Native limu specialist Wally Ito, who not too long ago retired as a coordinator with Cua’ana Ulu ‘Aumo, has spent the previous 50 years watching how invasive limu have outnumbered native species.

The Eva and Kahe shorelines had been as soon as prized for his or her considerable limu varieties. Ito remembers the seashores being lined in varied shades of inexperienced, which had been picked up by the locals to take dwelling.

The Limu inhabitants elevated when elevated urbanization and agriculture inland affected the groundwater that the Limu wanted to thrive within the coastal waters. When invasive species had been launched into Hawaiian waters for aquaculture within the Seventies and 80s, the native limu did not stand an opportunity.

Ito now spends time sharing his data of the limu with communities who want to restore it to their shoreline. Generally known as Uncle Valley, he usually takes college students and different members of the neighborhood on a “limu stroll,” the place he’ll survey the developments and varieties of limu on varied Oahu seashores.

There are a lot of shades of limu, each actually and figuratively. It is not simply good limu vs dangerous limu. Scientists have to consider how invasive algae are negatively and positively affecting whole ecosystems.

Limu is a supply of meals for limpets, urchins and fish, and it serves as a protecting dwelling for small marine life. Some limu additionally help make sand and forming rocks.

“It is not nearly controlling ‘dangerous’ limu,” Okano stated. “We even have to consider what we did to those ecosystems.”

Limu want nutrient-rich groundwater to reside, however when human influences pollute it, the native limu may undertake invasive traits. Wastewater, cesspools, land improvement and conventional agriculture can all have critical impacts.

“The father or mother species will develop actually quick, attempting to soak up all these vitamins,” Gibson stated. “But when there may be an excessive amount of algae, it should begin to rot and deplete oxygen, forcing the fish to go away.”

Complicating the matter additional is local weather change, notably the results of rising sea ranges and warming waters.

Kano Morishige, the coordinator of Na Maka Onaona, has studied the limu, opihi and haukeyuk (urchin) populations. She predicts that Limu will die again as a result of prolonged durations of excessive temperatures and small wave speeds. That, in flip, can change the fish’s weight loss plan and habitat whereas creating room for invasive species to thrive.

“If the timing of those sorts of features of the environment modifications, it might probably truly offset the expansion of those populations on the whole,” she stated.

Sustaining the mandatory steadiness of an ecosystem is difficult, she stated, and it is just worsened by invasive species and out-of-season modifications within the water.

With over 500 recognized species in Hawaii, Nicole Yamase is aware of we’re simply originally of understanding limu and the way it grows. The Micronesian doctoral candidate appreciates learning limu in Hawaii due to its significance to Hawaiian tradition.

“I actually wish to deliver this connection dwelling and bridge these data gaps,” she stated.

Nicole Yamase carried out her experiments outdoors the Annuenue Fisheries Analysis Heart in Honolulu. She is holding the alga Microdictian sechellianum, which is taken into account one of many extra frequent species present in Hawaii. Courtesy of Nicole Yamasse

Hawaii had a whole lot of cultural practices with limu due to its abundance and accessibility. So what if there may be much less native limu?

“No limu, no tradition,” Yamase stated.

As Hawaii considers 2022 the “12 months of the Limu,” there may be nonetheless a lot to be taught. However for Yamase, it exhibits that folks care about bringing native Limu data and consciousness to the neighborhood. She is presently learning limu artwork, a species that Ito hopes will change into the state limu.

Morishige stated it is extra than simply studying about limu as a meals; It’s a approach of bringing folks collectively and advocating for conventional knowledge.

“Limu traditions are tied to an intimate understanding of place and an aristocracy that our fishermen and folks have for his or her wider communities,” she stated.

And the Limu coal mine would be the proverbial canary relating to the well being of our close by ecosystems, she stated, so it is vital to concentrate to it. She is aware of that if the limu modifications, it should have an effect on the Opihi and Haukeyuk populations, then the fish inhabitants and the meals chain as a result of all these methods are interconnected and rely on one another to thrive.

“Limu can be our first indicator on the shoreline so far as what is occurring at sea and on land,” Morishige stated.

Civil Beat’s local weather change protection is supported by the Hawaii Neighborhood Basis’s Environmental Funders Group, the Hawaii Neighborhood Basis’s Marisala Fund, and the Frost Household Basis.

,Hawaii GrownPartially funded by grants from the Ulupono Fund in Hawaii Neighborhood Basis and the Frost Household Basis.



Supply hyperlink

Related Posts