The lush mangrove trees stand out prominently on the left and right of the coastline of Air Pessy Hamlet, Piru Village, West Seram District, Maluku.
On the deserted coast, you can see La Samiun and his wife, Wa Ima, in a boat. Both are seaweed fishermen. Samiun lifted three sacks of seaweed seeds. Under the water, seaweed is tied to a nylon rope.
Using the end of the oar, La Samiun lifted the rope to the surface of the water and then dropped it again. “This is so the moss and mud don’t stick,” he told Mongabay at the end of April.
This cultivation method is called a long line. The ( vegetative ) seeds of seaweed ( Eucheuma Cottonii) weighing 100-200 grams are tied in knots 15–30 cm apart on 30 meters long nylon rope.
Stretched on the main rope with a distance of 1.6 meters, there are piles called raft heads. There are also large ball buoys attached at certain points. Then additional plastic bottles were tied around the rope.
From planting to harvesting, La Samiun has to wait around 45 days. He doesn’t harvest all the seaweed, some of it is made into seeds for the next cycle. This method is commonly used by local seaweed cultivators.
Although seaweed can be planted all year round, good yields are greatly influenced by the east monsoon, which usually blows from April to October.
“This April, the east monsoon [east monsoon] should be blowing. It is still the west monsoon [west monsoon]. Maybe the impact of [climate change],” said La Samiun.
The east monsoon, which marks the dry season, is eagerly awaited by cultivators, including La Samiun.
When the east monsoon blows, it will make the longline plastic bottle bollard constantly sway according to the movement of the water. The effect will help the growth of seaweed fertile and more productive.
Conversely, when the west monsoon occurs in November–March, which is marked by rain, the growth of seaweed will slow down. Especially in 2023, even though April is almost over, the east monsoon never blows.
Quoting the BMKG website, the peak of the 2023 dry season in most areas is predicted to occur in July and August in as many as 507 Season Zones (ZOM) (72.53%).
When compared to normal, most areas, namely 402 ZOM (57.51%), are predicted to be the same. Meanwhile, other regions have advanced from normal 185 ZOM (26.47%) and retreated to normal 112 ZOM (16.02%)
To work around this, La Samiun also said that he often raises longline ropes to the surface of the water when it is hot and there is wind. Conversely, if it rains, he lowers it under water more than 50 cm.
This is agreed upon by Ode Sarifudin, another seaweed cultivator in Air Pessy Hamlet. He said that the change in seasons, followed by changes in sea temperature, made his plants susceptible to disease. Seaweed will return to normal when the east monsoon blows.
Changes in sea temperature can indeed bring a disease of seaweed called ice-ice. On the surface of the plant appear red spots that slowly turn pale. Furthermore, the growth of seaweed slows down, becomes brittle and the thallus stem breaks off.
The cause is ice-ice bacteria which spread when the temperature of the water conditions ranges from 31-32 C, at depths of 28-93 cm and current speeds of 7.1-11 meters per second. At that time the number of bacteria could reach 18,060 grams/colony [Supatno et al, 2010].
Referring to Santoso and Tri’s research . ice-ice changes in extreme environmental conditions, such as changes in salinity, water temperature, and light intensity
When the monsoons change, generally the majority of cultivators in Wael Hamlet move to the bay which is near the hamlet, the waters in this location are shadier, accompanied by wind so the water moves easily.
However, until this April they have not moved their place, because the monsoons have not yet blown.
“In the past, the east monsoon blew in March. 2020-2022, shift to April,” said Ramli, a resident of Wael Hamlet. “This year it will miss again, it is likely that May will just blow.”
He said everything was uncertain. In fact, in previous years, during a month like this, they were getting ready to move.
Another method was chosen by Udin, another grass cultivator. Due to uncertainty, he chose not to cultivate seaweed in large quantities. The area of the sea area, approximately 2 hectares, is only partially filled.
The main cause is the shifting of the seasons and the changing weather. One day, it was hot in the morning and afternoon and it suddenly rained. Under these conditions, seaweed growth slows down due to decreased biomass.
Muhammad Fadli, First Researcher in Oceanography Physics at the Ambon BRIN Deep Sea Research Center, explained that the weather changes in a day, sometimes hot and rainy due to the La Nina phenomenon that has hit Indonesia from 2020-2022.
Another impact, the dry season shifted to the rainy season. He said, to return to normal it might take 1-2 years. This phenomenon also affects monsoons so that it rains more dominantly, while the dry season becomes shorter.
La Nina and El Nino should occur every 4-7 years. However, climate change is making the duration even shorter.
Related to the shift in seasons, Fadli said, rain certainly increases river discharge and causes flooding. If the forest on land is still dense, there will be no problem with sedimentation. However, if the forest is damaged, sedimentation is easily lifted to the surface, causing the water to become cloudy quickly.
Fadli’s explanation is true. Due to the hydrological conditions of the waters used as seaweed cultivation sites, there is mud, sand mixed with mud, rock fragments, seagrass beds, and mangrove trees.
In addition, there are small and large-scale river mouths along the seaside. For example, in Wael Hamlet, there is the Wai Momon River. Plus the forest cover on the mainland is decreasing.
Syahidin Ali Maruf, a cultivator from Wael Hamlet, said that when high-intensity rains are followed by flooding, the waters often turn yellow. These conditions damaged the seaweed like what happened in February-March 2023.
Seaweed So Mainstay
La Ombo (56), is one of the first four people to restart seaweed farming in Wael Hamlet. Previously they had stopped because the sago factory management waste polluted these waters in 2016.
La Ombo also stopped, but between 2018 -2020 he returned to cultivating seaweed. When restarting, the seaweed was damaged and the crop failed. After trying slowly his efforts bear good fruit. He was also able to sell his seaweed.
“Per kilogram costs Rp 24 thousand,” he explained. The total harvest of seaweed at that time was 4 tons, initially 1 ton was sold, and the price was IDR 30 million.
But in 2023 the crop yields have declined. Once the harvest is sold, you can only get Rp. 600 -Rp. 700 thousand. Climate change is the main cause.
“Usually it takes 45 days to harvest, now it’s only 2 months faster and you have to harvest soon. So the weight of the seaweed will eventually decrease,” he explained.
When met by the Head of the West Seram District Fisheries Office, Moxin Pelu, stated that seaweed cultivation in West Seram is the mainstay of fishermen and the prima donna of this district. In general, cultivators are small-scale fishermen.
He said the 2022 concentration points for cultivators are on Osi Island and Wael Hamlet.
He continued, the price of seaweed is now higher than in previous years. For those that have been dried, prices vary between IDR 24 – 30 thousand and IDR 5 thousand wets.
The buyers are from Ambon and several businessmen in Piru, the capital city of West Seram Regency.