Category Archive Conservation

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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Latest news from the eels of KwaZulu-Natal

Last year, we’ve been granted a Foundational Biodiversity Information Programme grant to investigate the distribution and genetic diversity of Freshwater eels in the main rivers of KwaZulu-Natal. The project started in July 2016 and we just ended the field work.

This project aims to evaluate the change in historical distribution and genetic diversity of Anguillid eels along the East Coast of KwaZulu-Natal. To achieve these aims the following objectives have been proposed:

  1. Review the historical distribution (based on museum records) of freshwater eels in KwaZulu-Natal,
  2. Evaluate the change in distribution of freshwater eels in KwaZulu-Natal,
  3. Evaluate the genetic variability of freshwater eels from populations in main rivers of KwaZulu-Natal.

In the last two months, we focused our sampling effort in under-represented and under-sampled areas of the province where historical data was available as well as local knowledge. We then travelled to the Umtamvuna, Umzimkhulu, Umgeni, Thukela and the North Coast where we caught 15 eels (and 3 species Anguilla mossambica, A. marmorata and A. bengalensis labiata). Here are a few photos !

NB : All eels were released back where we caught them. It has to be noted that we work under a strict ethical code of conduct and that no fish were harm in any case. 

Guests at Zingela River Safari were really keen to learn about eels !

This eel caught in the Thukela was a little bit too big for our measuring pipe ! This is a giant mottled eel (A. marmorata) measuring 119 cm !

This African mottled eel, A. bengalensis labiata, has got some sharp teeth !

Setting some fyke nets and rafting in the Thukela

Electrofishing in the Thukela

Longfin eel (A. mossambica) caught in Harding in a farm dam !

Dr Peter Calverley, happy to help in Zingela ! Thanks to him for most of the photo presented here and all the help !

Setting fyke nets can sometimes be quite adventurous !

A pretty looking Longfin eel caught in Palm Lakes Estate. What do you think of that coloration ?

All the occurence data and barcode will be available ealy in the new year via GBIF and BOLD database.

We received tremendous help from local conservancies, fisherman, landowners and other enthusiasts and we want to really thank them for them help ! We would like to especially thank Michael House Nature Reserve, Donovale Farming, Palmiet Nature Reserve, the Payn Familly from Harding, Ben from Leitch Landscape, Helene and Paul from Simbithi Eco Estate, Dave and Chris from Palm Lakes Estate, Peter and everyone else at Zingela River Safari for their contribution (access, accomodation, warm welcome, help on the field and equipment).

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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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A survey in the Pungwe

During February and July 2017, Mahomed Desai, senior researcher and PhD candidate was part of a team that undertook an ecological survey within a selected area of the Pungwe Catchment in Mozambique.

Figure 1 3D Layout of the Pungwe Basin (Tinley, 1977)

The Pungwe River is shared between Mozambique (95% of the basin, generating 65-70% of the runoff) and Zimbabwe (5% of the basin, generating 30-35% of the runoff). The Pungwe River and its associated tributaries are highly dynamic and possess a relatively high diversity of habitat and biotope types, possibly due to the geomorphological nature of the system. The Pungwe mainstem can be described as torrential and is possibly due to the predominance of bedrock in the system as well as the topographical nature of the catchment. However, the river widens and flattens as it traverses the southern tip of the African Rift Valley – See Figures 2 and 3.

Figure 2 The southern tip of the East African Rift Valley system (WildCam Lab, 2017)

Figure 3 Photographs illustrating the Pungwe River (clockwise from top left) – Upstream view from the boundary of the Rift Valley during the low flow season; downstream view from the boundary of the Rift Valley during the low flow season; the Pungwe Gorge wherein the entire river is constrained into a relatively narrow gorge (to get an idea of the scale the depth off the edge was greater than 7 m) and deploying a fyke net in the Pungwe River (the bridge in the background is the boundary of the Rift Valley)
One of the major tributaries of the Pungwe River within the survey area is the Muazi River. The river is also bedrock-dominated (Figure 4). During the low flow season the turbidity of the system reduces and supports a population of Hydrostachys polymorpha, a rheophilic aquatic macrophyte (Figure 4). The species is currently listed as ‘Vulnerable’ and plays an important role in supporting an array of aquatic biota. In addition, within the survey area there are numerous creeks with a gravel and sand thalweg that drain into the system (Figure 4). These creeks provide a refuge area for various aquatic biota but these are however seasonal. Nevertheless, during low or zero flow periods there are isolated pools connected by sub-surface flow that provide habitat.

Figure 4 Photographs illustrating the Muazi River, a major tributary of the Pungwe River (clockwise from top left) – Downstream view exhibiting rapid-pool complex typical of the reach; angling in a large active channel pool; underwater photograph illustrating Hydrostachys polymorpha, an aquatic macrophyte listed as ‘Vulnerable and one of the numerous creeks that drain into the Muazi River (only isolated pools connected by sub-surface flow present during the low flow season)
As a consequence of the relatively high diversity of habitat types and biotopes within the system, including the survey area, the region supports a relatively high level of biodiversity, both terrestrial and aquatic. Of special interest within a regional context are the ichthyofauna, Odonata and terrestrial insects. These organisms although not as visible as other ‘charismatic’ species such as birds or larger mammals nevertheless are important in maintaining ecosystem processes and thereby overall wellbeing. A total of 38 species of ichthyofauna were recorded during both seasonal surveys and were typical of the Zambezian fauna. The dominant families were Cyprinidae, Mochokidae and Mormyridae. The ichthyofauna and formed unique communities within the system based on availability of cover features and substrate preferences, per redundancy analyses. Figure 5 illustrates some of the species recorded within the survey area.

Figure 5 Examples of the ichthyofauna of the survey area (clockwise from top left) Cyphomyrus discorynchus; Syndodontis zambezensis; Zaireichthys rotundiceps; Opsaridium zambezense; Marcusenius macrolepidotus and Hydrocynus vittatus

In addition, a new species or species complex of Chiloglanis (Mochokidae W. K. H. Peters, 1868) was recorded for the survey area (Figure 6). The species was typically associated with rapids and runs and utilised aquatic macrophytes, rocky crevices and cobble/boulder substrates as cover. Although data does not exist on dietary requirements, based on closely related species, it is assumed to feed on “aufwuchs” or the periphyton and invertebrate community that inhabit sold surfaces of lotic systems.

Figure 6 Top row – Photographs illustrating the lateral (left) and ventral view (right) of Chiloglanis sp. nov. Bottom row – Boxplot indicating catch per unit effort of Chiloglanis sp. nov. across hydraulic biotopes sampled. Dark horizontal line represents the median value, whisker represents 95th percentile and dots represent outliers
Due to the characteristics and size of the system as well as its inherent biodiversity, the system provides an array of ecosystem services to local communities and to society within a larger regional context. These services are varied and include subsistence fisheries, sediment deposition for agriculture, raw materials and pest control amongst others (Figure 7). However, no formal quantitative or qualitative studies have been undertaken and these are postulated based on previous knowledge from other systems and observations during the survey periods. Therefore, future research of this subject within the region should be considered if funding is available.

Figure 7 Examples of the range of ecosystem services provided by the Pungwe system (clockwise from top left) Fish trap made from reeds used during the high flow season; fish trap used during low flow periods; subsistence fishing is an important activity for local communities; maize fields in floodplain; Odonata are important pest-control agents and raw materials harvested for construction

Although the region possesses a substantial level of biodiversity the only formally protected area is Gorongosa National Park (GNP), located within the Lower Pungwe River. The Pungwe River delineates the southern boundary of GNP (Figure 8). Seasonal flooding from the Pungwe inundates shallow pans and oxbow channels on the Rift Valley plain at the southern end of the park. This flooding is vital for the newly constructed 6200 ha wildlife sanctuary near Chitengo and the DingeDinge Marshes at the confluence of the Pungwe and Urema rivers. During the high flow season, the Pungwe River branches and forms the Nhanvu River that flows into the Urema River upstream of Lake Urema and subsequently the Muaredze River before joining back into the Pungwe River. During the dry season, the Nhanvu River transforms into a series of pans (Figure 8). Nevertheless, these pans perform a vital function by providing refuge and/or nursery habitats evidenced by the relative abundance of Enteromius species, including E. haasianus, and juvenile life-stages of species recorded within the respective pans during the survey (Figure 8). During the high flow season when connectivity to the Pungwe River is restored, species are able to disperse and colonise new available habitat. Therefore, the connectivity between the pans and the Pungwe River is regarded as critical to maintain the wellbeing of the local ichthyofauna population.

Figure 8 Photos to illustrate the Pungwe River at Gorongosa National Park (clockwise from top left) Pungwe River during sunset; one of the pans fed by the Pungwe River via the Nhanvu River during high flows; pans linked to the Pungwe via the Nhanvu River are important refuge and nursery areas once isolated during the low flow season and Crocodylus niloticus at Lake Urema

At present, there are no significant water resources development projects in the Pungwe River basin in Mozambique. However, demand to harness Pungwe waters for inter-basin water transfer, municipal water supply, salinity control, hydropower, flood mitigation, large irrigated agriculture (sugar) schemes, and other uses is increasing. Furthermore, unsustainable use of the system and its catchment is leading to a decline in biodiversity and ecosystem wellbeing. Given the substantial socio-ecological importance of the system, it must be sustainably managed in a holistic manner involving all stakeholders as well as formally conserved in key areas.

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The Hunt for Rare Fish

During the week of the 10th – 14th October several members of our research group, Dr. Gordon O’Brien, Mahomed Desai, Céline Hanzen and Lungelo Madiya, who were accompanied by Ezemvelo KZN Wildlife Aquatic Ecologist, Skhumbuzo Khubheka, went on a survey to locate some of our rarer fish species in Northern KZN. The area falls within the uSuthu-Mhlathuze Water Management Area and includes South Africa’s first World Heritage Site, the iSimangaliso Wetland Park as well as the Maputaland Centre of Endemism. Apart from its ecological importance, the area is also utilised for an array of socio-economic activities.

This was a preliminary survey and was meant to confirm the presence of our target species in certain systems and to collect DNA samples. Further surveys will be more undertaken that will be more protracted to allow for effective and relatively comprehensive sampling at sites.

From left - Skhumbuzo Khubekha, Dr. Gordon O'Brien, Mahomed Desai, Lungelo Madiya and Céline Hanzen

From left – Skhumbuzo Khubekha, Dr. Gordon O’Brien, Mahomed Desai, Lungelo Madiya and Céline Hanzen

The first day was just set aside for travelling and brain-storming to identify possible sites where the species could be located. Our base was Hluhluwe-iMfolozi National Park.

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While the landscape is scenic and the large mammals attract many visitors , it is important to highlight and make the public aware that it is the smaller organisms that create a functioning ecosystem (such as the dung beetles pictured above). Whilst driving up from Durban we noticed that the area had received some rainfall which provided some respite from the drought that we are currently facing.

The first site was located on the southern end of Muzi Pan on the floodplain of the Mkuze River. Prior to sampling for fish we collected in situ water chemistry. With regards to this survey, fish were sampled using an electrofisher and seine nets. Thereafter, biotope details were recorded including depth, velocity, substrate and cover features.

Mahomed calibrating the water meters

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Lungelo and Skumbuzo ready for sampling !

 

 

 

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Brycinus lateralis

While the site yielded a relatively high diversity and abundance of species, none of our target species was recorded while going through the samples, until success; a single individual of a Brycinus lateralis was found! It is concerning that only a single individual was collected as unlike the other widespread Brycinus species in South Africa, B. lateralis is restricted to the Lake St. Lucia catchment.

 

The day we arrived, the Hluhluwe River in the reserve had reasonable flows compared to when we sampled there in September, when it was just a series of pools. Therefore, we decided to sample the river on the second day but outside of the park. However, when we arrived at our pre-selected site from Google Earth it was just a pool. Another success! We collected a few specimens of Micropanchax myaposae

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Pool on the Hluhluwe river

 

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Micropanchax myaposae (female)

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Micropanchax myaposae (male)

 

 

 

 

 

 

 

We were somewhat surprised at collecting a resaonable diversity of species at the site given that trucks were abstracting downstream as well as the presence of relatively large quantities of solid waste.

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Water abstraction on the Hluhluwe river

Furthermore, we wondered as to why the Hluhluwe river was flowing in the park but not where we had sampled. Then while looking at satellite imagery we identified a dam on the Hluhluwe River. The dam level was relatively low and consequently, there would need to be relatively high levels of precipation upstream in the catchment to fill the dam and to ensure adeqaute flows downstream.

 

 

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On day three the weather turned for the worse but we nevertheless sampled. The selected site was a swamp forest stream in suburbia in Richards Bay, a predominantly industry based town.

The site was dominated by Barringtonia racemosa, a protected tree, and possessed specimens of Voacanga thouarsii whilst the understorey was dominated by ferns. It was in this stream that we recorded 7 Clarias theodorae, another rare species that we were hoping to collect. Unfortunately, the stream is negatively impacted as surface runoff from nearby hardened surfaces drain into it and noticeable quantities of solid waste were present in certain sections. In addition, stormwater drains were present adjacent to the stream and if these are blocked with solid waste and spill, the water quality will deteriorate.
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Clarias theodorae

Clarias theodorae

Unfortunately we were not able to find some of the other species that we were searching for. Although we did collect the aforementioned species that we were targeting, they were never present in relatively high  abundances. There were several other sites that we had sampled but we did not collect any of our target species. Were they not present at these sites? or are they so cryptic that we could not collect them? Do they have particular habitat requirements? These are some of the questions that need answering.

We did notice that all of the sites that we sampled were negatively impacted by anthropegenic influences. If unsustanibaly utilised and/or mismanaged we could lose our natural heritage and their associated ecosystem goods and services, upon which society itself relies.

River Health Programme : Surveys in Northern KZN

While the fieldwork and draft report has been completed for the November 2014 to March 2016 increment of the River Health Programme, another round of sampling has been completed in September/October 2016. Specimens were collected, identified, DNA samples collected and biotope features where each species was collected was recorded.

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The W Primary Catchment – From the Umhlathuze to the uSuthu

The W Primary catchment is located in Northern KZN and spans from the Umhlathuze to the uSuthu River. A total of 17 sites are located in this area, with many being ecologically important due to presence of a relatively high level of freshwater biodiversity and species endemism for the province.

The area is not only important for freshwater biodiversity but terrestrial biodiversity as well.

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Many of the systems within the area were completely dry or not flowing due to the intense drought the country is presently experiencing.

However, some of the sites that retained pools were identified as important refuge areas for several species of fish as well as Odonates.

Key examples of this include a site on the Nwaku River that comprised of a series of pools where a total of 304 individuals from 6 species were recorded. Species recorded included Pseudocrenilabrus philander as well as the recently red-listed Enteromius gurneyi. 

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(c) christian Fry

 

Another important example was the site located on the Sikwebezi River. At this site the local landowner was fortunately supplying the system with surface water from his storage dam otherwise the site would have been completely dry.

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Thanks to his efforts in maintaining water in the system, a total of 167 individual fish were recorded, including juveniles of migratory species such as Labeo molybdinus and Labeobarbus natalensis.

Although some systems were possessed no flows, some of the larger systems were flowing and were identified as important areas for fish populations. Unfortunately, due to time constraints these sites were not sampled as comprehensively as warranted and the intention is to re-visit these sites to obtain a better understanding of the fish populations they possess. This included the sites on the Umhlathuze River as well as sites located within the Phongolo catchment. Below are some of the species that were recorded for these sites.

 

Unfortunately, many of the sites within the area were negatively impacted from anthropogenic activities and influences such as industry, illegal sand-mining, solid waste and over-grazing.

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Considering that society needs the ecosystem goods and services that freshwater ecosystems supply, it is critical that we effectively and sustainably manage the way we use our natural resources to ensure an optimum balance between protection and use. Education is also important if we are to ensure the protection of these vital ecosystems for the benefit of all.

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Sad news for the fish : 2016 IUCN revision of the conservation status of fishes in KZN

From the 19th to 23rd of September the Ezemvelo KZN Wildlife Freshwater Ecologist (Skhumbuzo Kubheka) and the leader of the Aquatic Ecosystem Research Programme (Dr. Gordon O’Brien) attended an IUCN red list assessment workshop for freshwater fishes in South and southern Africa. The workshop was attended by fisheries scientists from throughout the region representing many hundreds of years of experience from the region, including one of the “fathers” of southern African fishes; Prof. Paul Skelton.

KwaZulu-Natal has a relatively rich diversity of freshwater fishes with close to 100 species occurring in the province. Many of these fishes are endemic to the province, and many locally restricted populations of species believed to occur within the region have demonstrated to be new species restricted to KZN. In the last five years a number of new species of barbs, now classified as the genus Enteromius spp., mormyrids, cichlids, gobies and catfishes have been discovered and described or are being described.

With existing knowledge of our KZN fishes and this new species information UKZN and Ezemvelo KZN Wildlife were able to look for these fishes especially in areas where threats to the wellbeing of our aquatic ecosystems are known. Over the past three years we’ve been working in many rivers throughout the province as a part of our research with support from Ezemvelo KZN Wildlife, Umgeni Water, the Department of Water and Sanitation and the National Research Foundation. We have observed a concerning decline in the average diversity and abundance of many populations of fishes in the province. These changes have largely been associated with the change in distribution of alien fishes that predate and compete with our fishes, land-use practices, pollution and importantly, the current drought. There has been a considerable change in the availability of surface water in our rivers, dams and wetlands throughout the province with the coastal region of central and northern KZN especially threatened. Within this region, many rivers have dried out completely and remnant populations of fishes in pools and floodplain pans etc. have been removed due to pollution, habitat change and harvesting by local communities for subsistence and commercial trade. Although many of these systems normally fluctuate between a wet and dry phase with droughts periodically occurring, we have not observed such extreme conditions from 1990’s. During the drought of the 1990’s the threats to the wellbeing of the rivers were considerably less when compared to the threats to rivers today.

During the IUCN red list assessment workshop hosted by the South African National Biodiversity Institute (SANBI) held at the South African Institute of Aquatic Biodiversity (SAIAB) in Grahamstown, regional scientists and conservationists were able to review and address the conservation status of existing and new fishes in KZN. Key outcomes include the revision of a range of new fishes for the province and the listing of many species as threatened due to multiple stressors including land-use practices, water quality, flow and habitat alterations, disturbance to wildlife by many rural and urban communities, alien fishes and plants and the drought.

Noticeable outcomes include a reminder of the local extinction of the Maloti minnow from the Mkhomazana River below Sani Pass in the upper Mkomazi catchment in KZN. The historically common Redtail minnow (Enteromius gurneyi) has now been listed as a threatened species for the first time due to a lost almost half of its habitat and water quality and alien species threats. Two new freshwater dolphin fishes from the Mhlatuze River (Marcusenius caudisquamatus) and Mkuze River floodplain (Marcusenius kozi) have been discovered and immediately listed as Endangered and Data Deficient, which needs to have remaining locations verified urgently. We’re also now aware that the Chubby head minnow (Enteromius anoplus) populations are a complex of species which may need some protection when unpacked. Our local Striped robber (Brycinus lateralis) is also unique and may be listed as a protected species after we validate its remaining distribution in the floodplain region of northern KZN. Similarly, there seem to be a few new Stargazers (Amphillus spp.) in the province whose conservation status needs to be evaluated urgently. Our Bowstripe minnow (Enteromius viviparus) is also a unique species that is limited to KZN that makes this another endemic to the province. Our rare Inkomati chiselmouth from the Phongolo Catchment has been re-classified from the genus Varicorhinus to Labeobarbus nelspruitensis to complement the existing Natal scaly and Largescale yellowfish. With the establishment of many barriers to migration, such as dams and weirs, throughout the province we have seriously reduced the distribution of all four of our catchment scale migrating Anguillid eels in the province. These amazing migrators originate in the Indian Ocean, migrate into and up rivers where they can live for up to 40 years! Many of the eels we still have above many barriers may be remnants from a time before dams were built. We have a researcher in our group who will be looking into this issue over the next four years.  In consideration of the other rare fishes from the province including our snake catfish (Clarius theodorae) and coastal endemics the Blackspot climbing perch (Microctenopoma intermedium), Manyspined climbing perch (Ctenopoma multispine), Sibayi goby (Silhouettea sibayi), Natal topminnow (Aplocheilichthys myaposae), and the Killifishes (Nothobranchus spp.) we just don’t have enough information to address the conservation status of these species for now. We’ll also be turning some attention to this area with Ezemvelo KZN wildlife and looking into the current wellbeing of these species.

The take home message is that KwaZulu-Natal that had fewer than three freshwater fishes listed as threatened prior to the early 2000’s may now be tripled, with some species possibly being listed as Endangered or Critically Endangered. These fishes represent just less than a 10th of the freshwater fish diversity in the province, which now faces a real threat of extinction! All of us who live in the province need to use its water resources to obtain water for our homes and industries, we need to release wastes into them, harvest fish and swim in them, but we also need to care for them and the animals within them who also need them. You can only look after what you know so get into the game! Take your kid fishing! Go catch a Tigerfish or a yellowfish, put on some goggles and go and look for some minnows! And pick up a book about our rivers and what lives in them!