Author Archive AER Team

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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Bringing ecology into classrooms

A private school in the forests of Englewood New Jersey and a school in the mountains of Koshange KwaZulu Natal may not seem to have much in common but when speaking to the students about water quality it is apparent they share the same environmental concerns.
I was asked by Elisabeth Morrow’s 3rd grade class “what is an ecologist and why is water quality such an important aspect of our studies?” I thought it best to not just tell them each of the elements tested in a water quality assessment but to actually show them video footage of the Aquatic Ecology Research (AER) group at work. This prompted a dialogue about the importance of water and how we as humans don’t always do our part to take care of our resources.

 

In South Africa I got the opportunity to join LWAZI (‘knowledge’ in Zulu) on a school visit, as a representative of AER. LWAZI is an outreach project which focuses on encouraging underprivileged South African high school students to pursue a tertiary education. The initiative, started by Msc students Camille Fritsch and Olieve Fynn, allows UKZN students and interns to engage with teens by disseminating their research while also getting underprivileged students excited about science.

I held a similar conversation to that with Elisabeth Morrow, yet with an older group of nature enthusiasts from Sizisiwe High School. This school can be found in the mountains of Koshange, a modest town with panoramic views of the Drakensburg. I chose to use preserved macroinvertebrate and fish specimens collected by AER researchers. The students were intrigued by how as scientists we use insects and other species they recognize from childhood as indicators of water quality and overall ecosystem health. It hadn’t dawned on them how valuable an insect could be, or that our actions were ultimately disrupting entire ecosystems which in turn affect communities who rely on the services provided by that ecosystem. We discussed the need to decrease pollution and the more complex issue of how invasive alien species pose a threat. Our visit proved to be rewarding as I watched the matriculants go from enjoying an excuse not attend class, to proactively considering the environment and the role they each play.

 

Interning with the Aquatic Ecology Research group has been about more than just conducting field surveys of Kwa-Zulu Natal Rivers, but an opportunity to inspire a new generation of scientific researchers. It is integral to engage with young science enthusiasts and I hope to conduct more outreach with communities who may not understand the type of research we conduct but value our work nonetheless. The Aquatic Ecosystems Research group often enters remote communities to collect data for research or as part of the water monitoring project. Often times community members take notice of our presence. This has led to clashes where fishermen see our tools (primarily nets) and assume we are poachers. In my experience in the field, by engaging with the people we come across the tensions are eased and we actually find people want to know the results of our study. Our reach has spanned continents and ranged from sand miners to groups of women washing their clothing; even down to the young and curious helping to spot tadpoles.

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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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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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.

First field trip for our new team members !

It is time again for another River Health Programme round. Gordon and Céline, accompanied by the brand new team members, Carla Higgs, Mphatheni Mthembu and Fortunate Mashaphu conducted a site survey in the Umkomazana Catchment on the 09th February 2017.

Carla Higgs is one of our new PhD Students and she will focus her projects on ecological risk. Mphateni and Fortunate are master students who will respectively work in fisheries/river health and aquaculture. It was the occasion for our new members to train themselves in the field.

Gordon teaching Carla about SASS

Teaching how to use a clarity tube

The Umkomazana catchment is situated down Sani Pass, North of Himeville in KwaZulu Natal. It is one of major tributaries to the Umkomaas River, which enters it from the South. It has a longer upland valley section than the main river or its Northern tributaries, the Loteni and Inzinga. The Umkomazana River is a pool drop mountain stream and is 16 km in length. This entity once held a critical endangered cyprinid, the Maloti minnow, Pseudobarbus quathlambae and at the time it was recorded as showing a dramatic decline in population size following the introduction of trout to its habitat.  This species is now known to exist in six isolated Alpine populations in tributaries to the Orange River, Lesotho. The purpose of the survey was to conduct a survey (fish, invertebrates, diatoms, vegetation and water quality) in the framework of the River Health Program.

The team collected, measured, identified and recorded fish and invertebrates specimen. Presence of chubbyhead barb (Enteromius anoplus) is to be noted. DNA samples were collected for further analysis.

Welcome !

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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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