Staff Reporter
Changes in biodiversity and ocean chemistry, including ocean acidification, are among the factors that stakeholders within Namibia’s fisheries sector want the Fisheries Ministry to consider when determining the country’s Total Allowable Catch (TAC).
This was one of several issues highlighted during the recent Fisheries Indaba, which took place in Walvis Bay and brought various stakeholders in the fisheries sector together for open discussions.
Johannes Iitembu, Associate Professor of Fisheries Science at the University of Namibia, was among those who raised concerns about the issue. He noted that, despite evidence showing the importance of the ocean ecosystem, it is overlooked when it comes to TAC input.
“In terms of policies and legislation, there is an obligation for ecosystem consideration in our management approach, but when we look at the TAC recommendations, or TAC input, there is no consideration of the ecosystem,” Iitembu said.
This is a significant concern – and Dr Hilkka Ndjaula, Campus Director at the University of Namibia’s (UNAM) Sam Nujoma Marine and Coastal Resources Research Centre (SANUMARC), made that clear.
Speaking during a panel discussion at the Fisheries Indaba, Ndjaula explained that changes in ocean chemistry and biodiversity affect the abundance, distribution, reproduction and productivity of fish stocks. Understanding this data is therefore vital for decision-making in the fisheries industry.
“Temperatures are rising, the chemistry of the ocean is changing. We are hearing there’s ocean acidification. We are also understanding that, with harvest and other mortality factors, the biodiversity in our oceans are changing. And, as Namibia, we will need to know what are our thresholds when it comes to temperature, to the chemistry of our ocean, to the food web structure that we have, and, equally, what is our biodiversity like over time,” she said.
Ndjaula explained that understanding the environmental conditions that fish species in Namibian waters can tolerate is important when planning for the maintenance and restoration of marine ecosystem health, rather than simply committing to blanket, general solutions.
“If we do not know the biology that regulates the availability of those populations, then we are as good as just hoping for the next fish which we don’t know where it’ll come from,” Ndjaula warned.
She drew attention to the possibility that the habitats of certain fish species are changing, potentially owing to changes in the ocean. Thus, she noted, understanding the impact of these changes is also important when making decisions on data collection, as marine surveys have been conducted in the same areas over several years.
She questioned whether these survey sites remain suitable for monitoring fish stocks and whether the data they produce continues to provide an accurate picture of the stocks’ distribution.
“Are those still the habitats that we can use for monitoring those stocks? Has the dynamics of the ocean temperature, salinity or acidification caused the stocks to move somewhere and therefore we are managing with information coming from the same area that we surveyed for the past years, meanwhile the stock has moved? Those are the questions that we need to see and we need to understand,” she said.
Ndjaula emphasised that ensuring the credibility of these surveys is vital, as they influence management decisions, which in turn determine fishing targets and limits, impacting job security and the long-term health of the marine ecosystem.
“It’s science that will allow us to present evidence of where we are, where we were, where we want to go, and the sustainability that comes with it. I hope this Indaba will allow us to get back to what are our management triggers. What are the thresholds that we need to monitor so that when we reach tipping points, we have that evidence and we also have the advice from the science that we are able to stick to,” she continued.
Considering all this, Ndjaula suggested that it is time to review how data on Namibia’s ocean and marine life is gathered and to ensure that the information remains relevant and capable of informing management decisions.
She also encouraged the Ministry to ensure that its decisions are supported by data, including information on the impact of changes to the ocean ecosystem.
Photo: Ministry of Agriculture, Fisheries, Water & Land Reform
