Author Archives: EW

About EW

Endre Willassen Professor emeritus -zoology

Summing up the polychaete work

A species of bristle worms (Polychaeta) in a genus that has not previously been found in West Africa.

A species of bristle worms (Polychaeta) in a genus that has not previously been found in West Africa.

The workshop identified about 140 species of Polychaeta.At least 12 of the species are clearly new to science. Five genera that have not been recoded from African waters were also identified. 385 specimens were selected for DNA-barcoding.

Portrait of a crab

Sakaila africana was recognized as a new species by Raymond B. Manning and L.B. Holthuis in 1981. Their publication in The Smithsonian Contributions to Zoology is an important source  to the identification of West African crabs. An electronic version of the publication is available on this link. Our workshop found Sakaila africana in samples from Guinea Conakry.

Sakaila africana

Sakaila africana

Environmental monitoring in Ghana

On 10th July, the workshop was visited by guests from the Norwegian Institute of Marine Research who are doing field work in Africa from R/V Dr Fridtjof Nansen. Tor Ensrud gave a presentation of monitoring activities performed from the Nansen in Ghanaean waters. He showed pictures and impressive video clips from the prototype of a sampling rig equipped with ROV and 3-5 grabs. Some of the pictures can be seen at the IMR website.

Environmental monitoring in Ghana

Environmental monitoring in Ghana

Sorting the snails

Mollusca sorted for species identification

Mollusca sorted for species identification

When samples are sorted to main groups of taxa,  individuals can also be separated into “morphotypes” based on their general appearence, Morphotypes may or may not correspond to species and this has to be decided by more thorough examination for species identification.

A sample from an epibenthic sled

Different sampling tool are available for sampling animals. They will retrieve different parts of bottom fauna, depending also on factors such as net size, cruise speed, and the size and agility of the animals. An epibenthic sled can catch the animals that live on or just above the bottom surface. This sample on a sieve contains snails (Mollusca, Gastropoda), brittle stars (Echinodermata, Ophiura), polychaete worms (Polychaeta), shrimps, crabs and hermit crabs (Crustacea, Decapoda).

A sled sample from 30 m depth off Senegal.

A sled sample from 30 m depth off Senegal.

Temperature towards the deep waters

Annual surface temperature  according to oceanographic data in World Ocean Atlas (WOA09)

Annual surface temperature according to oceanographic data in World Ocean Atlas (WOA09).

Oceanographic data are showing hight temperatures in the tropical surface waters. However, the striking geographical differences become less when the measurements are taken in the deeper parts of the water column. Click this link to see a rough picture of how temperature changes towards the deeper layers.

(The animation was made by EW with Reiner Schlitzerands ODV and converted to a Windows Video File.)

Studies of East Atlantic bottom fauna

The University Museum of Bergen has acquired benthic samples from the West African continental shelf in agreement with the Guinea Current (GCLME) and Canary Current (CCLME) Large Marine Ecosystem projects.
MIWA first post-001

The first batch of unsorted bottom samples from the GCLME region, weighing 750 kg, arrived in Bergen October 2007.

The first batch of unsorted bottom samples from the GCLME region, weighing 750 kg, arrived in Bergen October 2007.

We study hundreds of samples to learn more about the rich species diversity of this region and to compare it with the  northern fauna.

Our permanent web pages can found be here: The Invertebrate Collections.

We also have a general blog for the collections, which can be found here (English) and here (Norwegian).

For interactive maps, sampling stations and other downloadable information about the MIWA-project, click here.

Publications stemming from the work can be found here.

Training activities, collaborations, and guest researchers

Our wonderful collaborators. Photos by various of the pictured, montage by K.Kongshavn

Our wonderful collaborators. Photos by various of the pictured, montage by K.Kongshavn

We have arranged six training activities on MIWA-material, including multiple species identification workshops, some of which were focusing on particular groups such as mollusks, polychaetes, and brittle stars.

A lot of people have been involved to make all of this happen. We have been fortunate in being able to attract excellent students and experts alike, and we have hosted over 35 research visits, including scientists from Columbia, France, Ghana, Mauritania, Nigeria, and the UK.

An overview of the projects on the different taxonomic groups found here.