Fish stock surge after completion of eco-friendly bridge
THE Mbita causeway that provides a strategic link between communities living in Rusinga Island in western Kenya has stood out as an architectural wonder for decades.
It was constructed in the early 1980s to link Rusinga Island to the mainland and facilitate movement of people, goods and services.
However, its construction was carried out without adequate consultations with environmentalist and marine experts who, over the years, have blamed it for dwindling stocks of fish in the Winam Gulf, located at the heart of Lake Victoria. Fish stock, though, is fast increasing in the gulf since the removal of the causeway two months ago.
“The black water current is freely flowing towards the gulf for the first time in many years,” said Gideon Nyaidho, a fishery assistant with the Department of Fisheries in charge of East Karachuonyo.
He noted the water within the gulf was currently hot and lots of fish were migrating to the side to hatch, a new development for the fisheries fraternity.
In the early 1990s, researchers at the Lake Victoria en- vironment management programme and Kenya Marine and Fisheries Research Institute did a study that found that the causeway had poor water quality, blocked fish migration and interfered with breeding patterns.
Political leaders also blamed the causeway for the miseries the fisherfolk endured in carrying out their trade.
Over time, scientists piled pressure on the government to remove the causeway, which they claimed blocked the freeflow of water across the lake, resulting in the near-death of one side of Winam Gulf.
As the flow of water remained blocked, the Gulf developed into a fertile breeding ground for the invasive water hyacinth that has been choking a huge swathe of Lake Victoria for two decades.
The government yielded to pressure and a demolition exercise began in earnest four years ago and has yielded a new flyover bridge that allows water to pass freely under it, towards the gulf.
Nyaidho noted that the gulf had reclaimed its hatching ground prowess, judging by “the latest activities along the beaches on the side of the lake”, a position it had once held since the early 1950s.
“We have to intensify surveillance to help protect the region from unscrupulous fishermen by ensuring that only fishermen who are using recommended gear fish in the area,” Nyaidho noted.
He told communities along the gulf to be on the lookout to ensure that fishermen used the right gear and fished during the specified period of time.
James Kingi, a fisherman along Siala beach, confirmed that fishing activity had improved, judging by the size of fish being caught.
Kingi, who has been fishing for the past 20 years, said the current development was indeed good news to them as the fish on the gulf side was almost finished, due to poor restocking from the southern side of the lake.
Fredrick Juma, a fishery assistant in West Karachuonyo, said riverine fish species were eliminated, as there was no access to deep water.
He added that as rivers emptied their contents, sometimes raw sewerage waste from towns and agricultural plantations remained as the water became shallow and toxic to marine life.
“The causeway permanently blocked a secondary connection between Rusinga Channel and the offshore waters of Lake Victoria towards the gulf, hence poor stocking of fish on the side,” he added.
An environmentalist with Osienala (Friends of Lake Victoria), Peter Mireri, noted that the channel, which was 250m in length and over 10m in depth, was blocked by the causeway, hence reducing the lake’s cleansing capacity.
He said that fishing activity had reduced on the side due to lack of flushing and exchange of water between the two shores.
“I welcome the demolition and the construction of the new bridge as a good gesture for the fisherfolk and the ecosystem of the lake,” Mireri added.
He revealed that despite destroying fish breeding grounds, the Mbita channel had also hampered shipping trade within the gulf.
According to Nyaidho, even though the channel had been a stumbling block to the fishing industry in the region, water hyacinth had equally caused headaches to fisher folk.
However, he said the introduction of beetles was contributing immensely to the demise of the weed, since the blankets of weed eaten by the insects were fast sinking, hence paving the way for hippo grass, which helped fish to grow with ease.
“The rotting hyacinth is creating some black mud that is today home to mud fish and catfish, popular delicacies with the locals,” he added.
He, however, noted that daily catch of tilapia and Nile perch had dropped drastically, due to the high demand for the two species.
“With the construction of the flyover bridge and proper patrol of the lake, I can see fishing activity booming once again, as was the case in the 60s and 70s,” Nyaidho added.
The 200m bridge that links Rusinga Island and Mbita mainland in Suba district, western Kenya, commissioned two months ago, was built at a cost of about $10.5 million. – ANA-Xinhua