Effect of climate change on fisheries ‘needs more research

MORE time is needed to research and monitor the effects of climate change on Namibian fisheries in order to address the challenges that will arise.

Chris Bartholomae, Chief Fisheries Biologist of the Ministry of Fisheries and Marine Resources, who spoke at the Fisheries and Aquaculture Conference held at Swakopmund last week, said over the last 400 000 years the earth’s climate has been unstable, with significant temperature changes, going from a warm climate to an ice age in as little as a few decades. He also said it would be impossible to unravel and identify the impact of climate change over a relatively short period such as the history of fisheries in Namibia.Because of this, he suggested that future research and monitoring efforts need to focus on much broader time and space scales.He said the Ministry was collaborating with German fisheries experts on a new project that will be implemented from next year until 2011 to research and to try and predict the impacts of climate change on the northern Benguela current.Bartholomae said there were several signs that may indicate that climate change has started affecting the Benguela System.These include a reduction in coastal upwelling, increased frequency and severity of Benguela El Nino events and an increase in average summer wind stress.”The effects of climate change [could also be] of low amplitude and general,” he said.The likely consequences of these changes could, according to him, lead to the cooling down of the productive upwelling system to a warm tropical low productive system, which would affect the entire ecosystem.”Fish distributions, species and abundance would change, which would force fisheries to be flexible and adaptive to deal with such a changing system,” he stated.”It is important to see the signs for what they really are and to act or adapt accordingly.”According to Larry Hatching of the Department of Environment and Tourism in South Africa, there is considerable connectivity with South Africa and Angola in terms of water exchange and overlapping stocks.He also said it would be impossible to unravel and identify the impact of climate change over a relatively short period such as the history of fisheries in Namibia.Because of this, he suggested that future research and monitoring efforts need to focus on much broader time and space scales.He said the Ministry was collaborating with German fisheries experts on a new project that will be implemented from next year until 2011 to research and to try and predict the impacts of climate change on the northern Benguela current.Bartholomae said there were several signs that may indicate that climate change has started affecting the Benguela System.These include a reduction in coastal upwelling, increased frequency and severity of Benguela El Nino events and an increase in average summer wind stress.”The effects of climate change [could also be] of low amplitude and general,” he said.The likely consequences of these changes could, according to him, lead to the cooling down of the productive upwelling system to a warm tropical low productive system, which would affect the entire ecosystem.”Fish distributions, species and abundance would change, which would force fisheries to be flexible and adaptive to deal with such a changing system,” he stated.”It is important to see the signs for what they really are and to act or adapt accordingly.”According to Larry Hatching of the Department of Environment and Tourism in South Africa, there is considerable connectivity with South Africa and Angola in terms of water exchange and overlapping stocks.