Tag Archives: wasini island

Leopard Tortoise

While on the journey back from a mangrove walk last week we spotted something rare and unusual – a giant leopard tortoise (Stigmochelys pardalis)! Leopard tortoises are historically absent from the coast and this species on Wasini island is most probably introduced at some point. We had once before seen a small leopard tortoise on the island of Wasini – but it had been killed and brought to base so we never imagined one would survive to grow so large!

The tortoise’s straight carapace length (SCL) was about 30cm, and straight carpace width (SCW) was around 20, hiding under prickley undergrowth near to the main path from Wasini to Mkwiro. We quietly took a photograph for later identification and left it where it was. – later we identified it as the Leopard Tortoise; the fourth largest in the world reaching up to 46cm in length. This tortoise is herbivourous and each individual is uniquely patterned with black markings.

Tortoise seen by Mkwiro mangroves

Tortoise seen by Mkwiro mangroves

An update from Marine’s bird surveys

The past 6 weeks we have been continuing our bird surveys on the island and have generally been a bit more attentive as to the different species we see around base! Mangroves can be an important habitat for nesting and feeding of migratory birds, and this coastal area is home to several species of marine bird species – however we have also been finding an abundance of forest and thicket dwelling birds making their homes here too. 

The Brown Noddy - a new species added to our bird list (picture taken from Helm Birds of East Africa Field Guide

The Brown Noddy - a new species added to our bird list (picture taken from Helm Birds of East Africa Field Guide

We are happy to share that we have spotted 6 bird species that we haven’t yet recorded on the island and added these to our species list! These include the Brown Noddy (Anous stolidus), an offshore feeding sea tern, the Green Wood Hoopoe (Phoeniculus purpureus) which is iridescent, forest inhabiting and endemic to Africa and the White Browed Coucal (Centropus superciliosus) a relative to the cuckoo found in thickets and grasslands often near water. We have also had confirmed sightings of the Malachite Kingfisher (Alcedo cristata), the Plain backed Sunbird (Anthreptes reichenowi), and the Brown headed Parrot (Poicephalus Meyeri). We will continue the bird surveys over the next few weeks and hopefully we will find some more interesting birds we did not realise were present on the island.

Bird surveys on Marine

My first week on marine as part of the staff team has been busy, but very exiting! I have been dong some extra work in terms of the bird surveys that we want to start doing in different locations around Wasini Island, and I have been looking at the data collected in the mangroves since the first expo in 2007. I found that more than 40 bird species have been seen around the island during this time. 

The Collared sunbird spotted on Mkwiro base

The Collared sunbird spotted on Mkwiro base

The most frequently seen include the Fork tailed drongo, Black kite, Grey heron, Palm nut vulture, Yellow billed stork, Western reef heron, African fish eagle, and a few different Egrets and Ibises. Starting this week we will conduct at least two bird surveys around the island in the mangroves but also in other areas including the forest patches and rocky shelf areas. Interestingly, this week we have already spotted two beautiful Collared Sunbirds and an African Paradise Flycatcher. We also added a new species to our bird list – the Lesser Noddy. Hopefully we will spot some more species in the different habitats around Wasini Island. It will also be interesting to compare the species we find around here to the ones on the other side in Shimoni. Watch this space!

Big Plans for Mkwiro Mangroves

During the last few months, we have focused more attention on the important mangrove ecosystems present on Wasini Island – they are integral to a healthy coastal ecosystem and also represent an essential resource for the local communities. We have ascertained the dominant tree species present in our mangroves to be the Red Mangrove (Rhizophora mucronata), with lesser species including the White mangrove (Avicennia marina) and Yellow Mangrove (Ceriops tagal). We have also developed a comprehensive species list from incidental and casual sightings.

View of various Mangrove species

View of various Mangrove species

Over the next three months, we will be developing surveys to assess zonation of flora and fauna in the mangroves using random sampling and quadrats along set transects.

Seed Pods

Seed Pods

These results will give information about the distribution of species, habitat associations and assist making in re-planting projects successful by determining the optimum location to plant the seed pods.

More turtles spotted in the channel!

Since setting up a new transect outside our Mkwiro base we have been seeing more and more turtles in the Wasini channel. Most of them are spotted at the Eastern end of the channel where you can find both coral and sea grass. Whilst we have had a small number of Hawksbill sightings, it appears to be mostly Green turtles that are being recorded, including sadly, a dead one.

 

Green Turtle seen surfacing in Wasini Channel

Green Turtle seen surfacing in Wasini Channel

Adult Green turtles are normally found around coastlines and in protected areas where there are sea grass beds. These turtles are the only species that once they are adults are entirely herbivorous. Their preferred habitat automatically puts them in danger from increasing human activity, particularly boat traffic and pollution and as a result they are classified as endangered by the International Union for the Conservation of Nature (IUCN).

The fact that we are spotting Green turtles on a regular basis in the channel may indicate that this is an important feeding or resting area, this remains to be seen but the data is definitely useful when trying to manage the Green Turtle populations in Kenya.

Mangrove Forests

Along the Eastern edge of the African continent, the Indian Ocean supports a distinct set of coastal zones, one of which being mangrove forests. The zonation and distribution of different habitats is determined by physical conditions, including type of substrate, tidal and current regimes and the influence of fresh water.

Mangrove forest consists of a few species of salt tolerant, terrestrial evergreen trees. In particular in the Western Indian Ocean there are nine species of mangrove that are commonly seen. Covering 22 million hectares worldwide, they represent one of the most productive and diverse wetlands on the planet.

Mangrove forests are specialised in a number of different ways, adapting to cope with the salinity of the seawater by pumping excessive salt ions to specific leaves on the tree, falling once levels have been steadied.

The commonly encountered ‘Yellow Mangrove’ (Ceriops tagal), utilises buoyant propagules that fall from the trees and sharp-ended tips can establish themselves in the soft ground, growing into a new mangrove tree.

Local Mangrove species near Wasini Island

Local Mangrove species near Wasini Island

Failing this, the propagule will then float vertically in the water, promoting it chances to root as the tide goes out.

Mangrove forests have historically received less public awareness than other globally important habitats and supporting such a large number of animal and human populations, it is crucial that it is conserved. Over the past 50 years, mangrove forests have been damaged all over the world by anthropogenic pressures, such as tourism, overharvesting of trees and shrimp aquacultures. Therefore we need to protect this link between marine and terrestrial habitats and in turn conserve the surrounding wildlife.

Having completed abundance surveys for the species in Wasini Island’s mangroves over the past 2 years, this expedition GVI is going to develop the research to include surveys to try and identify any species zonation that is present on the island and the factors that might influence the mangrove’s distribution. Our first trip out with the GPS was a success, plotting waypoints to Sea Turtle skeletons found in the roots and other key marker points of interest. We’ll keep you posted on future developments of the mangroves!

Leathery surprise!

We recently spotted a leatherback turtle (Dermochelys coriacea) in the Wasini Channel. This is an unusual sighting due to the fact that Leatherbacks are normally found more offshore. Leatherbacks are unique in terms of sea turtles as all other species have carapaces made of keratin (like what our finger nails and hair is made of), whereas a Leatherback’s carapace is made of a thin rubbery layer that is reinforced by hundreds of tiny bony plates. This enables them to dive deeper (over 1000m) as their carapace is more flexible than other turtles.

Leatherbacks feed almost exclusively on jellyfish and although they have the largest north south range of all sea turtles they are classed as critically endangered by the International Union for the Conservation of Nature (IUCN). This is largely due to the fact that they confuse plastic for jellyfish as well as getting caught in commercial fishing nets. Due to the above this makes our sighting all that more important. Unfortunately we were unable to get a picture in time. Whether it was a stray or we actually have resident Leatherbacks off the coast of Wasini remains to be seen but we will be keeping our eyes wide open!

Coral Substrate

This expedition sees the start of another exciting underwater survey!!! With our newly acquired underwater camera we will be taking photographs of the coral substrate found along the transects that we snorkel. This will allow us to obtain information on the diversity of the coral found in and around the Kisite Marine Protected Area. This information will then be linked to the new reef fish survey that was started last expedition.

Hard coral substrate

Hard coral substrate

Establishing which coral species are present is an important indicator of how the reef is doing and also which reef fish may be present. Many reef fish have a specific relationship with the coral, for example, butterfly fish and parrotfish that feed on coral. Certain species of Butterflyfish favour certain species of coral, thus if there is a decline in the number of parrotfish or butterflyfish on a reef then we can assume that there is some level of disturbance affecting the corals. Corals are living beings that are made up of coral polyps and an algae called zooathalae living in a symbiotic relationship and are very sensitive to changes in water temperature, salinity. Thus studying the coral substrate is an important addition to our data.

The Elusive Humpback

I was sitting outside the cottage discussing the different types of hornbills found in Kenya, as a Trumpeter Hornbill had just flown over head, when Sergi (the marine officer of expedition 094) pulled me aside to talk about my independent project. I was secretly chuffed that I got given the one I did, as there was a choice of three. The title of my project was “Data Analysis of Indo-Pacific Humpback Dolphins (Sousa chinesis) collected by GVI Kenya Marine Team from 2006-2009.”
 HBD sightings

These animals are very shy animals and are not as well known as the bottlenose dolphins. Maybe because they are shy or perhaps because of their habitat distribution, there is very little data available. So this was a great opportunity to be able to provide some information. The GVI Marine Team has been collecting data on them since 2006. Whilst out on the boat on a survey day, if we have a spotting we follow them around, taking photos and also monitor their behaviour. Using a GPS (Global Positioning System) we are able to plot the route taken by the dolphins that day.  This allows us to see the areas where the humpbacks dolphins feed, rest, socialise, breed etc. As well as being able to gain data on group sizes and composition.

 So I went forth and did some research on our friends the humpbacks and also plotted the information on our study area (see picture) which is the Kisite-Mpunguti Marine Park and Reserve and the surrounding area.
 Humpback dolphins occur in small groups (3-7) and are distributed throughout Indian and Western Pacific oceans as well as the coast of south east Africa. Inhabiting tropical and subtropical waters (15oC – 20oC), they prefer coasts with mangroves, rocky reefs, estuaries and lagoons. Typically found in waters less than 20m depth, they only venture a few miles from the shore line (as shown on the map), and occasionally they swim up rivers. The distinctive hump on their dorsal fin gives rise to their name; and they are medium sized 2.5m – 2.8m.
 

boat trWasini channel and the surrounding waters are prone to quite a lot of boat traffic and fishing. Humpbacks tend to avoid boats, although marks caused by propellers have been observed. This is a concern not only because of the damaged caused to the dolphin but also because of the resultant change in their behaviour, e.g. leaving the area. Another concern is that being situated on the coast; the communities living here depend upon fishing as a resource. Recent efforts have been made to educate some of the local community as to the importance and implications of over-fishing and pollutants.

 HBD spyhopping

It is my aim to develop a catalogue of the humpback dolphins, as this will allow us to determine population numbers and residency rates in this region. This is a technique called mark-recapture, and it uses the dorsal fins to identify each individual, mostly from the notches made by other dolphin or boats, but also by the shape, colour and size of the fins. Plus, on the cheeky side I will get to name some of them!

Sarah Watson was a conservation intern on 094 Expedition, and is currently doing her work placement with GVI, as staff member on the Marine and Terrestrial Programmes

Nyuli Conservation Group Training

Nyuli Community Conservation Group is a new group of villagers from Mkwiro village, who are interested to establishing a community marine protected area off Nyuli Reef, which is close to Wasini Island. They are going to have 10 rangers, who are going to be patrolling the area to stop illegal fishing (mainly ring nets and spear gun-fishing) and 22 tour guides, who will take tourist to snorkel on the pristine coral reef of Nyuli or on dolphin-watching tours to see the different species of dolphins and whales.

amber-and-cody-during-the-interacting-with-tourists-lecture.jpg 

 Amber and Cody during the “interacting with tourists” lecture
GVI met with the group to know how we could help them and they asked GVI to educate them on the importance of conservation and also to train them on working with tourists. And last Friday GVI volunteers and staff gave lectures on marine conservation as a whole, whales and dolphins (their behavior, morphology and diversity), as well as mangroves.  We were very happy to see their high level of enthusiasm and interest. The main message we tried to get across was for them not to overfish or use illegal fishing techniques, and I am pleased to say they understand the importance of these issues and how they relate to conservation.

ebrahim-acting-as-a-tour-guide-and-cody-as-a-tourist.jpg 

 Ebrahim acting as a tour guide, and Cody as a tourist
 

On Monday we gave lectures on sea turtles and reef fish which I think was quite intense, so when a lecture on “Interacting with tourists” followed the class got involved and they were laughing at each other role playing at being tour guides. Other than being entertaining, I honestly believe that they will make brilliant tour guides. At the end of the week they will have an exam on what we taught them so fingers crossed!!!

sarah-watson-explaining-the-diferent-families-of-reef-fish.jpg
Sarah Watson explaining the different families of reef fish