Category Archives: mpunguti island

Presenting Sea Turtles at the WIOMSA symposium

The next item GVI Kenya will be presenting on at the WIOMSA scientific symposium in Mombasa in October is the seasonal occurance and distribution of sea turtle sightings in and around the Kisite Mpunguti Marine Protected Area (KMMPA). We most commonly see Green and Hawksbill turtles both from the vessel and in-water while snorkelling, during our research days; with 41% and 53% of sightings prospectively.

Sea turtles are often seen surfacing from the research boat

Sea turtles are often seen surfacing from the research boat

Sea turtles were most commonly seen in two focal areas; the KMMPA and the Wasini Channel. We also conducted interviews with 75 fishermen whose responses corresponded with this, indicating that they encounter sea turtles most frequently (61%) in the Mpunguti Marine Reserve, and in the kaskazi season (January to March) with 29.5% of responses. We will be discussing the importance of the KMMPA and surrounding waters as critical habitats for Hawksbill and Green turtles, and how community education and awareness programmes will play an important role in conserving local populations.

Groups of Migrating Whales spotted

Since our first sighting of the Humpback Whales on the 21st July, we have had three more sightings, with possibly up to 11 individuals seen. On the 29th July we encountered four whales in a group together, moving slowly, surfacing often and performing lob tailing behaviour. Previous years we have only seen groups of up to three whales together, so this was particularly exciting!

Three Humpback Whales were spotted in the shallows off Nyuli Reef

Three Humpback Whales were spotted in the shallows off Nyuli Reef

Our third sighting occured at Upper Mpunguti, just outside the Marine Reserve, with one smaller individual coming into very shallow waters and one Humpback Whale spotted both by our research vessel and the passing tourist boats, much deeper breaching over 10 times before disappearing from sight. And just this week we had our fourth and fifth sightings, one whale being spotted travelling between the two islands of the Marine Reserve and another heading west just behind Wasini island. We managed to also observe this individual from land with our telescope – and find that it was actually part of a group of 3 whales again breaching and travelling slowly past the coast.

Extended periods of lob-tailin was observed in 2 individuals

Extended periods of lob-tailing was observed in 2 individuals

Humpback Whale Season

The past couple of weeks on Marine we have been able to observe the beginning of the Humpback Whale migration northwards through the Kenyan waters. Our first sighting was a lone adult resting just outside the Mpunguti Marine Reserve, its location given away by its huge blow – the blow of a Humpback Whale can reach up to 8m allowing them to been seen from great distances. The individual breached its full body out of the water a number of times demonstrating agility for such a large mammal. 

The Humpback Whale breaches fully

The Humpback Whale breaches fully

 The lone adult was around 15m in length and was most likely a female; female Humpback Whales are generally larger than males at around 11-15m length. We aimed to take photographs of its dorsal fin to aid identification from previous years sightings and to compare with those from other organisations.

By photographing the dorsal fin we can try to identify this individual

By photographing the dorsal fin we can try to identify this individual

Humpback Whales are listed as endangered by the IUCN and are present over the East African coast  between July and October performing their huge annual migrations for breeding and calving, so these sightings represent crucial data on this species. As the season continues you will be hearing more frequent updates on our sightings.

SeaStars

Sea stars, also known as Starfish are echinoderms that are well known for their regenerative properties. Sea stars are capable of growing a new disc and arm. Most sea stars have 5 arms although several such as the Luidia maculata and the Acanthaster planci (Crown of thorns starfish) have more. Although we only record sightings of the Crown of thorns, due to their relationship with the destruction of coral, many different species of starfish are seen consistently on snorkel transects, the most common ones are described below.

We quite often spot thin limbed Linckia guildingi and Linckia laevigata  on shallow reef areas and among coral rubble – they have smooth, long cyclindrical arms and are around 25cm diameter. They are pale pink or gray and distinctive bright blue, and seen in a variety of areas both inside and outside the KMMPA.

Linckia laevigata - distinctive bright blue found on shallow reefs

Linckia laevigata - distinctive bright blue found on shallow reefs

Protoreaster lincki have a very distinctive appearance with a bright red pattern and spines on a pale grey or white body. They can reach around 30m diameter and have been seen in large numbers recently; 8 were seen on a snorkel transect on the northern edge of lower Mpunguti island in the Marine Reserve just this week.

On our rocky intertidal we are also fortunate to see species that prefer sandy or seagrass shallow areas such as the Pentaceraster mammillatus, with highly variable colours seen, and Pentaceraster tuberculatus, which is a bluish yellow.  These tend to have stocky bodies, with rounded tubercles on surface and reach up to 20cm diameter.  

Pentaceraster mammillatus with smooth tubercles in the centre

Pentaceraster mammillatus with smooth tubercles in the centre

Also, in our more degraded and heavily fished reef areas, such as those around Sii Island, we see a number of the mentioned species and also the Culcita schmideliana on the shallow reefs. It is a large, inflated five armed starfish growing up to 30cm in diameter. They are pale cream in colour towards end of arms with mottled pink on a red disc and have scattered black, blunt tubercles. These feed on small coral colonies.

Culcita schmideliana feeds on small coral colonies

Culcita schmideliana feeds on small coral colonies

We have a wealth of interesting marine species in this area, often overlooked due to the larger more iconic species also present here. Sea stars are one of many!

The diveristy of Ray species in the KMMPA

When out on the boat, or snorkeling a transect one of the most amazing megafauna we see are rays. There are over 30 species of rays from 10 different families. They have skeletons that are composed of cartilage rather than bone, so like sharks, they are known as a cartilaginous fish. The 3 most commonly spotted rays along the Kenyan coast are the spotted eagle ray, the blue-spotted ribbon tail ray and the manta ray.

The spotted eagle ray has a body length of up to 3.5 metres, with a white underside with a black dorsal surface with distinctive white spots. They have a long tail with serrated barbs at the base. They are found mainly on inshore shallow water around reefs all year round. Most recently we have seen this species on our snorkel transect in the Marine reserve – an individual over 2m in width moving gracefully over the reef.

Blue spotted ribbontail ray spotted hiding on one of our snorkel transects

Blue spotted ribbontail ray spotted hiding on one of our snorkel transects

The blue-spotted ribbon tail ray has an oval shaped body, up to 90cm in diameter. Yellow brown colouration with numerous blue spots. Their tail has a fleshy ridge, blue stripes and a single sting. They are generally solitary and common on rocky shores and coral reefs. They are seen in the marine park throughout the year, and have been seen on numerous snorkel transects around Kisite island, though they can be hard to spot due their ability to camouflage themselves in the sand. Just last week we spotted two a managed to get this great photograph on Snorkel Transect 7.

Manta rays are the largest ray at a width of up to 6.7 metres and a possible weight of over 2000kg. They have a wide head with a pair of paddle like flaps at the front and possess 5 pairs of gill openings that are well equipped for filtering plankton. They have a black dorsal surface and a white ventral surface. Being very powerful swimmers they can jump clear of the surface of the water (which is thought to dislodge parasites). They are seasonal visitors to the marine park, being found mainly between January and the end of March. Found mainly in deeper water but occasionally spotted close to the reefs. In 2002 up to 500 manta rays were seen between Kisite and Sii Island, and just yesterday our boat captain spotted one leaping clear of the water in the marine reserve.

Progress with our Reef Fish Surveys

In a blog earlier this year we discussed our plans for developing and improving reef fish surveys in Kisite Mpunguti Marine Protected Area. We thought it was time for an update…

We have been busy doing surveys 1 and 2 on almost all of our survey transects through this and the previous expedition, with volunteers and staff both learning to identify and estimate the sizes of different families and species of important reef fish. Survey 1 assesses coral health by using bio-indicator species so in this survey we look at butterfly and angelfish and Survey 2 assesses the relationship between trigger fish, sea urchins and herbivorous fish including surgeon and parrot fish. Both these surveys give a good indication of the health and stability of the different reefs and the levels of biodiversity. This study will also help to determine the impact of fishing on the coral reef communities. Even in these initial stages it is possible to identify some key trends and differences between the transects and reefs surveyed.

Lethrinidae lethrinus nebulosus - the number and size of Emperor fish are recorded for Survey 3

Lethrinidae lethrinus nebulosus - caught for consumption - the number and size of Emperor fish are recorded for Survey 3

Survey 3, which focuses on commercially important fish including the following families; Emperors (lethrinids), Snappers (lutjanids), Groupers (serranidae) and Rabbitfish (siganidae), indicates the impacts of fishing by recording differences in abundance and size on transects within and around the Marine Park. This week we have had 4 people pass the required identification test and are ready to start surveying! We have 4 weeks left of this expedition and we aim to cover each transects at least once for each survey. It’s going to involve a lot of snorkeling and although challenging, it’ll also be really interesting.

Solitary predators of the reef

Over the last few weeks we’ve been lucky enough to see a variety of eels whilst snorkelling off the reefs of the KMMPA (Kisite-Mpunguti Marine Protected Area). Eels are one of our lesser spotted inhabitants, often hiding in holes and crevasses. So you’ll need a good eye if you want to spot one. They come in various shapes, sizes, colours and patterns; recently some of the key species we have seen are the Blackspotted Moray and the Giant Moray which can reach lengths of betwwen 6 and 8ft, and the Peppered Moray the Spotted Snake Eel and Tiger Snake Eel, which are white to yellow colouration with distinct black spotting, of differing patterns and are slightly smaller at maximum lengths of around 4ft.

Hidden away these solitary predators lie in wait, jaws a gasp waiting for any unsuspecting fish, crab or octopus to get that little bit to close and BANG! Dinner is served! With lightning fast reactions the eel grabs its reckless and unsuspecting prey and drags it still wriggling (in a feeble and futile attempt to escape) back down into its deep, dark lair hidden within the coral.

An eel hides in the crevasses of the coral reefs

An eel hides in the crevasses of the coral reefs

 These sinister looking creatures are awesome to watch, their heads protruding from the dark recesses of their makeshift home, slowly rocking back an fourth with the current, watching, waiting and ever vigilant. They’re very sleek predators and if you’re lucky enough to spot one you’ll be glad you’re not a reef fish.

Sousa chinensis

Over the last four years sightings of humpback dolphins (Sousa chinensis) in Wasini channel have declined.  This expedition there has been just one sighting of a humpback dolphins (not including mixed species groups).  Part of the reason for this could be the wider (and more offshore) survey area we are surveying, whereas humpback dolphins’ habitat is close to the coast.

In search of humpback dolphins we travelled west, along the mangroves of the Kenyan mainland.  The waters are shallow and the bottom is sandy, ideal for humpback dolphins.  In the calm waters we could see for miles, but when we spotted some dolphins they were just 20 meters from the boat.  It turned out to be a mother and a newborn, we can tell by the small size of the calf and the swimming pattern of the pair.  Soon we realised there was a third dolphin, another calf.  This is excellent news, particularly given the possible decline of the resident population.

Humpback Dolphin Mother and Calf

Humpback Dolphin Mother and Calf

As we studied the behaviour of this small group, we soon realised there was a fourth dolphin, keeping separate from the others.  It was a large humpback with multiple scars and marks on its dorsal fin and a disfigured tail.  Our boat captain noted that this male has been seen in the Wasini area on many occasions over the last few years, around the coasts we survey.

This was an exceptional day, to re-find humpback dolphins, and to find calves.  We will continue to survey the mangroves to the west and also eastwards, to Funzi bay, in order to better understand our humpback habitat.

Johnny Zabari, December 2010

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