Fish

Category Archive Fish

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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Tales of a 6-months internship with the AER Team by Emily Winter

Emily Winter shares some of the highlights of her six-month internship with the Aquatic Ecosystem Research Group.

Back in April, I was pleased to be met with a welcoming and enthusiastic group at UKZN, who readily introducing me to the research themes, team members and field sites. I was eager to challenge myself and quickly got stuck into some fish surgery practice with Céline and Matthew, in preparation for the FishTrack project in the uMngeni catchment. I soon overcame my fear of croc-infested waters and could be found checking nets and electro-fishing at Fountain Hill Estate in search of the Natal yellowfish. I was excited to be assisting Matthew and co in the development of their new, real-time telemetry project.

Assisting Matt in catching yellow fish in Fountainhill Estate (Wartburg)

While also assisting with the quarterly REMP (River Eco Status Monitoring Programme) surveys, my own project was developing under the watchful eyes of Gordon and Celine, and in June I joined the SAPPI team to explore the lower Thukela catchment and monitor its fish and invertebrate communities. A hypothesis was born, and I focussed my investigations on the use of the Nembe and eMandeni tributaries by fish when the Thukela river is in flux. My fish identification and surveying skills progressed rapidly with the support of Mahomed, particularly in distinguishing between the small barb (Enteromius) species, and I was proud to be able to lead similar surveys in July and August. The opportunity to survey the Thukela fishway with Gordon, David and Mphatheni was a particular highlight, with initial results suggesting that the structure does not function as a migration corridor as well as would be hoped.

Conducting REMP surveys in the Umgeni with Fortunate and Pumla.

In the final few months, I was very fortunate to be invited to contribute towards international efforts for a review paper on African fish migrations (yet to be published). The experience has been invaluable in developing my scientific critique, writing and collaboration skills and I have learnt a considerable amount about African freshwater ecology in the process. Despite returning to Europe, I am excited about continuing this trend, maintaining connections with my new South African friends and colleagues, and developing ways in which we can work together in the future. With the help of Mahomed, I will be remotely completing the ‘Tributary Refuge’ project on the Thukela and I look forward to sharing the results with the wider research community when the time comes.

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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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Sampling through the cold front

The team started off the River Eco-status Monitoring Program (REMP) second quarter (July-September, 2017) with the Thugela and uMngeni River catchments. The Thugela catchment team headed for central KZN and included the Mkomazana river along Sani pass. While the Umgeni team surveyed along the uMngeni River with a few sites in the Mlazi River. It so happened that a cold front swept over the province during the week of surveying creating magnificence views of KwaZulu-Natal back-dropped by the Drakensburg mountains covered in snow. The front made for some interesting weather to survey in with cold winds and temperatures.

The survey went well and even contributed to some of the genetic work the AER is doing on barbs Enteromius sp and freshwater eels, Anguilla sp.

In total 3 eels were caught, one on the Mooi River upstream from the Mooi-Thukela confluence and two on the Mlazi. All the eels were Anguilla mossambicus.  Eight E. anoplus were caught on the Mkomazana River near Sani Pass, while ever hopefull of catching the Maloti minnouw (Pseudobarbus quathlambae) there. Other barbs, E. gurneyi were caught on the Karkloof river in the Umgeni Catchment.

With over 3000km driven so far the REMP second quarter is off to a good start. We still have the southern and northern sites to do.

A survey in the Thukela estuary

The University of KwaZulu Natal (UKZN), Unit: Aquatic Ecosystem Research (AER) conducted a  survey to Thukela Estuary on the 19th-26th March 2017. The participants for this survey were Mphatheni Mthembu, Lungelo Madiya, Nombuso Gongo and Jennifer Cele. The Thukela estuary is situated approximately 100 km north of the city of Durban in KwaZulu-Natal. This estuary is shallow with relatively small surface area and has a large catchment area. It is one of an open river mouth estuarine system in South Africa thus making this entity more abundance and diverse in terms of species than temporal open/closed or closed estuaries. This entity is an importance estuary to humans and marine species supplying goods and services that can range from nursery grounds, fisheries, to recreational amenities. The purpose of the survey was to track and monitor changes in the Thukela estuary and ultimately determine the causes and effect for the identified changes.

OUTCOMES

The AER estuary team noted with concern the dynamism of this estuary in that the sediment deposited was slightly higher than previous surveys thus causing high sand exposure during low tide. The team suspected this years (2017) early flood for this increased sediment deposition in the estuary.

The Thukela estuary during low tide

The AER Team also noted that the Thukela estuary had a low salinity which indicated that this entity is dominated by the Thukela river input. This could be the cause for low marine fish species number and abundance found in the middle and upper reaches of the estuary.

The YSI water meter showing water quality reading of Thukela estuary

The AER estuary team used cast nets, fyke nets, gill nets and seine nets for sampling. It was noted that the seine net sampling efficiency was higher during cold days. The seine net also caught significant higher fish species than other nets combined. The fish caught were collected, measured, identified and recorded. The team found more fish species in the lower reaches of the estuary and the fish caught were dominated by juvenile marine taxa in those lower reaches of the estuary. These juvenile marine taxa were not high in species number as expected but were abundance. The most dominating species caught in this estuary were Mugilidae (Mullet), Caranx neberi (blacktip kingfish), Leiognathus equula (Slimy) Ambassis natalensis (Slender glassy) and Ambassis gymnocephalus (Bald glassy) although there are some species that are still to be identified which were not caught in large numbers.

The estuary team also collected benthos samples using the grab for laboratory analyzes. The water quality samples were also collected. The team noted with concern a variety of fishing activities taking place in the Thukela estuary, including illegal, largely subsistence gillnetting and they catch big fishes which were ready to spawn. These gillnetting are combined such that there could cover 2/3 or whole estuary across. These gillnetting efforts have been commercially driven by selling fishes to markets.

CONCLUSION

In conclusion, The AER group noted that the estuary was highly dynamic with high sediment exposure during low tide compared to previous survey. The group was also concerned with the extreme long gillnets used by locals for fishing. The group also noted high abundance of fish species as one move closer to the lower reaches of the estuary. This site survey proved to be useful for updating information in the Aquatic Ecosystem Research in University of KwaZulu Natal.

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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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.