Category Archive Fish behavior

Let the fish swim : send Matt and Céline to Australia !

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Promoting fish migration awareness at Epworth Primary School

The Aquatic Ecosystem Research team was invited to Epworth Primary School to give a presentation about World Fish Migration Day (WFMD) to the grade 4-7 pupils on the 1stof June 2018. WFMD is a global event coordinated by the World Fish Migration Foundation to highlight the importance of migratory fish and river connectivity.

In connection with the WFMD theme, “connecting fish, rivers and people”, the AER team spoke to the pupils about the importance of river connectivity for not only migratory fish, but the community at large. The presentation included a video, The Duzi Gold, which showcases the obstacles that migratory fish have to get over in order to access resources and suitable habitats. There were some indigenous fish on display for the students to have a look at which they were VERY excited to see! There was also a fish swimway (fish ladder) model on display and the students were quite fascinated to learn how the ladder can allow fish to swim over a weir or dam! Students were also given the opportunity to play their own role our understanding of the importance of river connectivity by “adopting a fish” whose behavior will be monitored in a KZN yellowfish tagging survey as part of the uMngeni Fish track study lead by the AER Group.

If you are keen to support this project by adopting a fish, contact us Pumla or Matthew. If you’d like to to organise a visit to your school, let us know !

Few photos for Solly Pecket (Epworth School) from this great outing !

(c) Solly Pecket

(c) Solly Pecket

(c) Solly Peckett

(c) Solly Pecket

 

 

 

 

 

 

 

 

 

 

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We were busy celebrating the World Fish Migration Day 2018 !

The Aquatic Ecosystem Research team has been busy with World Fish Migration Day 21st April 2018: Kruger National Park – Sabie River, Palmiet River and Msunduzi/uMngeni River.

World fish migration day (WFMD) is an event held globally every two years aquatic scientist with support from the World Fish Migration Foundation (WFMF). The WFMF encourages scientist within water resource research to host an event locally to create awareness for the migration of fish, promoting the connectivity of rivers and the work they are doing to contribute to river connectivity. The Aquatic Ecosystem Research (AER) group within the CWRR at UKZN co-hosted with WFMF (a team of Dutch scientists) and South African National Parks (SANParks) an event within the Kruger National Park. This event became the WFMD headquarters for Africa. The event extended over three days ending on the 21st of April in Skukuza Rest Camp and had various activities all focusing around fish connectivity within Rivers, and the benefits of having healthy fish to have healthy Rivers and healthy people.

On the day the book “From Sea to Source 2.0: Protection and restoration of fish migration in rivers worldwide” was launched. The book contained articles from all over the world on different problems and solutions to fish migrations three small chapters were written by Dr Gordon O’Brien programme leader for the AER-UKZN group. The book was handed over to and warmly received by the Managing Executive of KNP Mr Glenn Philips. Other SANParks official along with the Department of Environmental Affairs and Tourism (DEAT) for Limpopo and environmental consulting companies attended the event.

Leading up to the day, Kanniedood Dam near Shingwedzi Rest Camp was demolished using explosives as part of the KNP’s water management policy to restore the parks natural water distribution and improve river connectivity. Further natural science pupils from local schools were invited to be educated on the topic of fish migrations and interact with local and international scientist and managers, with the Sabie River weir and gauging station used as demonstrations. The students were given the chance to see some of the local fish species as the AER team showed them how to catch fish and do SASS5 monitoring. Other activities for the event included: Press releases from local and international news organisations, fishway demonstrations, face paints, a small aquarium with local species (15 species were on display) and posters of the research the AER-UKZN group are involved in.

The team involvement in Kruger also lead to a nice article in the Sunday Citizen, that you can read here.

Here within KwaZulu-Natal the AER hosted two other events. The first event took place on the 11 March to accommodate the high-school canoe races, the second took place within the Palmiet River event on the 21st April. The canoe race was co-hosted with the girls from St Anne’s High School. The challenge was to paddle the race upstream instead of downstream. The idea was warmly received, and the kids got first-hand experience of what fish go through when migrating upstream. The kids got fully involved tackling rapids, current and dams to get to the finish line. The whole event was filmed and presented to the world on World Fish Migration Day in Skukuza, KNP and launched online. The theme around the video was ‘Duzi Gold’ with yellowfish being equated to a living commodity as valuable as gold. Check out our video by searching for ‘Duzi Gold’ online to see the paddlers paddling upstream.

The Palmiet River event was co-hosted with the Palmiet River Valley Conservancy (PRVC). The Palmiet River was selected as it flows directly into the Umgeni River Estuary and is a socio-economically important system, despite the many problems it faces as an urban river. The socio-ecological importance of fish communities was highlighted, as well as the multiple stressors negatively influencing them, particularly within the Palmiet River. The event had various public interaction sessions with an array of activities. An aquarium housing the species caught within the Palmiet were on show, this included a 900 mm eel which became the centre of attention. Maps were placed on displays providing information to the public. In addition, citizen science tools (miniSASS and the clarity tube) were demonstrated. Members of the public were encouraged to take cognisance of the environmental impacts around them and to take action.

 

All in all, World Fish Migration Day was a great success! The various events held by the AER-UKZN team with support from the CWRR centre all drew in the crowds and created much needed awareness towards the connectivity of Rivers. We all started thinking of how well-connected our rivers are, particularly the uMgeni River. Not only are we fighting pollution issues’ but we need to create free flowing rivers within the catchments we find ourselves in.

 

Follow these links to learn more.

World Fish Migration Day: https://www.worldfishmigrationday.com/

From Sea to Source 2.0: Protection and restoration of fish migration in rivers worldwide: https://jonesriver.org/getfile/herringcount/FromSeaToSource2.0.pdf

Duzi Gold Series

 

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A tagging study : movements of KwaZulu-Natal yellowfish in the upper uMngeni River.

Riverine ecosystems are affected by anthropogenic activities and environmental changes. One of the ways in which to evaluate the effect of these impacts is assessing the behaviour ecology of fish populations. Fish behaviour tells us how fish adapt to human activities (survival and recruitment) and how they improve their use of ecosystem resources. Behavioural variables include habitat selection, reproduction and reproductive strategies and migration behaviour. Information on fish behaviour can be used in conservation of fish and the aquatic ecosystems they occupy.

As part of a study on the uMngeni River we will be looking at the reproductive biology and migration behaviour of the KwaZulu-Natal yellowfish (Labeobarbus natalensis). This involves evaluating the location, timing and duration of spawning migrations of yellowfish in the uMngeni River. Thus far, 22 yellowfish have been tagged with VI tags (Figure 1) at the inlet of the uMngeni River into Midmar dam, with the intention to tag more over time. We would like to call on all anglers in the upper uMgeni River for the assistance in recording data from any tagged yellowfish they may catch as this will aid the study immensely.

We need your help ! In the event that a tagged yellowfish is caught please, at best, take note of the following and let us know:

1. The location (include site coordinates if possible)
2. The date
3. The VI tag number (e.g. D 55)
4. The standard length of the fish (mm)*
5. The weight of the fish (g)
6.Note any abnormalities (e.g. deformity, disease or injury)
7. Photo of VI tag and full body photo (see examples below)

Figure 1: Orange arrows shows : on the left, the placement of the VI tag behind the eye, and on the right the placement of the VI tag in relation to the body of the fish.

Please Contact the following people below with any information or questions:
Pumla Dlamini: pumladlamini1@gmail.com, Matthew Burnett: matthew@riversoflife.co.za and Dr. Gordon O’Bien: obrien@ukzn.ac.za

 

* Standard length :

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Tagging Natal Yellowfish in the uMngeni River

The tagging of Natal Yellowfish (Labeobarbus natalensis) in the uMngeni River,

Figure 1: One of the tagged Natal Yellowfish at Albert Falls dam, showing the good size and condition of fish needed for tagging.

As part of the uMngeni Fish track study headed up by the Aquatic Ecosystem Research Group a yellowfish tagging survey was organised. This is for the component of the real time remote monitoring project that is crucial in assisting AER to understanding Natal Yellowfish behaviour and establishing the remote monitoring network. Having tagged fish in the river will allow the team to assess yellowfish movements and strategically place water probes and remote stations to obtain data in real time. This is exciting to see as some of the results start to come in.
The AER team went out to Albert Falls Dam and Fountain Hill Estate to tag Natal Yellowfish. The fish were caught using gillnets and electro-shocking. Gill nets were monitored constantly to prevent injury to fish. Suitable fish were remove from the net immediately on capture and then transferred to a holding net. Electroshocking was using in shallow fast flowing rocky habitats, suitable fish caught were transferred to a holding net. In total 3 fish were acquired that were fit to be tagged.

Figure 2: Catching yellowfish using the electro-shocking method at Fountain Hill Estate, one can see the yellowfish in front of the excited researchers

Tagging procedures took place under 17 minutes for each fish. The procedure requires surgically implanting of the tag into the abdominal cavity. Two fish surgeons were scrubbed up to maintain a sterile environment while operating, the surgical equipment was sterilized beforehand in an autoclave and opened on site during the operation. Assistants helped handle the fish and non-sterile equipment while the surgeons operated. These steps were taken to create a sterile environment around the incision to prevent infection. The following steps were taken to ensure a smooth quick operation; Fish were anaesthetized using phenoxyethanol. Once signs of narcosis were shown, the fish was then moved onto the operating table and put into position. A pipe pumping water over its gills was maintain throughout the operation to minimize exposure of the fish to the air. An incision was then made in the area between the pelvic fins and anal fin into the abdominal cavity being careful not to cut too close to the anus or pelvic fins. This insertion cuts through to the abdominal cavity were the tag is the inserted. The tags aerial is set using a spinal needle and then once the tag is in place the abdomen is stitched up using suture material. Wound-gel is then applied over the wound to protect it from bacterial infection and allow the mucus layer to recover. To further assist with this anti-biotics are applied. Finally, the fish is placed into a recovery container and held there until signs of narcosis are no longer evident. The fish is then release by allowing it to swim away from the tagger.

All three fish were successfully tagged and released. The Fountain Hill yellowfish named “Drone” is already swimming around one of our remote stations and providing us with valuable data. The two Albert Falls yellowfish (named David and Fortunate) were released and picked-up within the dam later in the day. The AER team is currently setting up the remote network to be able to track them. The tagging procedure was a great success and will get better as we expand the study showing how fish can help us monitor the environment in real time.

Figure 3: Shows the release of the Natal Yellowfish after the tagging procedure, swimming freely on its own.

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Our aquarium facilities

The Aquatic Ecosystem Research (AER) Aquarium is located at University of KwaZulu-Natal, Pietermaritzburg campus. The main purpose of building this facility is for fisheries scientists to conduct research on behalf of the department. Research to be conducted includes culture of Mozambique Tilapia, Oreochromis mossambicus, which will be used as feed for crocodile culture project, which aims to evaluate the suitability of fish as crocodile feed. Cultured Tilapia will also be used for a study that focus on evaluating the suitability of crocodile carcass as protein source for fish culture. some of the tanks will be used to culture O. mossambicus populations sampled from different rivers around KwaZulu-Natal to select suitable population for conservation of the species for Aquaculture purposes. O. mossambicus broodstock will be collected from Unizulu and culture experiment will be initiated.

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Culture of Yellowfish will also be conducted in the aquarium to carry out a tag retention study on the KwZulu-Natal yellowfish, Labeobarbus natalensis. Comparing different tagging techniques and the use of external versus internal tags within a tropical environment.in terms of the aquarium progress, currently tanks, pipes and filters has been installed and the system is running very well and is in good condition for fish culture.

The following colleagues are acknowledged for operating the aquarium in success; Dr Gordon O’Brien, Matthew Burnett, Fortunate Mahlatse Mashaphu and Rendani Luthada-Raswiswi.

INVITATION – Dialogue to celebrate the World Fisheries Day and workshop on SA Fish Swimway Programme

We are pleased to announce that the SA Fish Swimway Programme will be hosting a workshop on the 21st of November 2016 in Pretoria. The University of KwaZulu Natal, together with WRC and SA Fish Swimway Programme Partners, will be hosting an event to celebrate World Fisheries Day. This will include presentations by fish specialists, followed by discussions reviewing the Swimway programme and refining the next steps. One of the speakers will be Mathew Ross, who in 2015 completed his PhD on fishway design in South Africa.  Representatives from the Kingfisher Project have also been invited, to talk about the current plans for Catchment Management Agencies in South Africa. During the workshop, we would like to specifically refine a suitable proposal that can be used for funding applications relating to fish migration in South Africa. We hope you will be able to attend ! 

Interested ? Please RSVP events@wrc.co.za

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In the press – “Namibia takes pride in freshwater fisheries resources” by Francois Jacobs

Our team member and PhD. student Francois Jacobs (and representative of the Ministry of Fisheries and Marine Resources of Namibia) is involved in one of the largest freshwater fish-tagging programmes in southern Africa.

This tagging programme is a long-term marking and recapture study for target species such as the African tigerfish, Hydrocynus vittatus, Threespot bream, Oreochromis andersonii and Nembwe, Serranochromis robustus. An article aimed at raising public awareness has been published in “Stywe Lyne/Tight Lines” (August 2016).

What if you find a tagged fish !? Please refer to the article, here.

Fish catches bird in flight !

A population of African tigerfish, Hydrocynus vittatus, from the Schroder Dam, actively prey on barn swallows, Hirundo rustica, in flight. This behaviour was discovered during a radio telemetry study and documented using a motion picture video camera. These results show that an avivorous diet is a part of the feeding biology of H. vittatus, and may occur in other populations.

Read the full article here, published in the Journal of Fish Biology in 2014.

Take a look at the video !

Read the post on Nature Publishing Group website here.