Scientists from the Department of Ichthyology and Fisheries Science at Rhodes 老虎机游戏_pt老虎机-平台*官网 initiated a fish and fisheries research project at Flamingo Lodge in 2005. Initially, much of our research focussed on basic aspects such as describing the species composition in the area and examining the biology of the common species caught at the lodge. We also started a catch monitoring and tagging study at the lodge in 2005. The most interesting findings were a new species of Geelbek (Atractosciondifsii). We are busy writing the description of this species at the moment. We also found new range extensions for several species, including Newtons Wrasse (Thalassoma newtoni – see picture below), which was previously only thought to occur exclusively off the islands of São Tomé and Príncipe. Our biological research showed that the species captured at Flamingo (Leervis, Kob and Shad) are fast growing species, that mature within 3 years.
In 2008, we were awarded a grant to conduct research on the artisanal fish and fisheries around Flamingo Lodge. We partnered with the 老虎机游戏_pt老虎机-平台*官网 of Agostinho Neto in Luanda and conducted social and economic research on the local fisheries. We found that a 1kg fish caught by the guests at Flamingo Lodge brought USD 54 to the local economy, compared with USD 22 for the same fish caught in the artisanal fishery and USD 8 for the same fish captured in the subsistence fishery. This highlights the importance of the lodge to the local economy. We also found that the dominant fishes targeted in the artisanal and subsistence fisheries were very slow growing, late maturing and susceptible to exploitation.
In 2011, we were awarded a grant to gain an understanding of the impact of the formation of the Benguela Current on the evolution of fish in the region. We selected 12 species, ranging from sharks to Octopus that are common to South Africa and southern Angola and found, using genetic analysis, that they had all been separated approximately 2 million years ago when the cold Benguela Current formed. Not all of the species have reacted to the separation in the same way. For example, some fishes on either side of the Benguela Current have evolved into different species, while others have retained very similar characteristics. We are busy trying to understand why this is the case.
The oceanography of southern Angola appears to be changing rapidly. Our recent research has shown that the sea temperature in this region is heating faster (0.8°C per decade) than anywhere else on earth. For cold blooded animals such as fish, even small changes in water temperature have a major influence on their metabolism and physiology. Our research has shown that migratory species, such as the kob (Argyrosomus coronus) has shifted its distribution south into Namibia over the last 20 years. Resident species will respond differently to migratory species. For example, our research has shown that the reproduction of resident fish such as the blacktail (Diplodus capensis) may cease in as little as 70 years in Angola.
Our latest project is looking at the movement and migration patterns of marine animals. In 2013, we partnered with the Ocean Tracking Network (oceantrackingnetwork.org/) from Canada and have placed a series of acoustic receivers, with help from the Angolan Ministry of Fisheries in the southern Angolan coastal waters. The placement of the receivers is designed to understand the movements, evaluate the importance coastal embayments and examine the daily movement patterns of migratory marine animals in the coastal zone of southern Angola. We have surgically implanted acoustic transmitters into 20 adult kob (Argyrosomus coronus) and 20 adult leervis (Lichia amia) and aim to monitor their movements for the next two years. Besides expanding the acoustic receiver array throughout Angola, we plan to tag and monitor the movements of several marine species, including turtles, in the near future.
For further information on our research, including publications and popular articles, please contact Dr Warren Potts (w.potts@ru.ac.za).
Last Modified: Thu, 04 Jun 2015 20:29:43 SAST
