Fishermen in Senegal and Mauritania say the mass production of fishmeal by foreigners is depleting fish stocks.
BBC World Service
A meteorite that is one of the biggest pieces of the moon ever put up for sale is being auctioned online by a Boston based firm.
The moon rock, weighing about 5.5kg was found last year in a remote area of Mauritania.
It is thought to have plunged to earth thousands of years ago.
Its large size and composition are very unusual. It could fetch around $0.5m (£380,000) at auction.
A former slave who was released from bondage in 2008 is to stand in September's parliamentary elections, the anti-slavery group IRA-Mauritania says.
Habi Mint Rabah hopes to be elected as an MP for the recently formed IRA/Sawab coalition - which is comprised of IRA-Mauritania and the more established Sawab party.
"I became a slave at the age of five. Every day I had to take care of the cattle. Every night I was raped by my master," Ms Rabah said shortly after her release.
"I always thought, without really understanding, that it was normal."
Slavery was outlawed in Mauritania but remains widespread, according to human rights groups. Black people of certain ethnic groups are often enslaved as domestic workers by lighter-skinned Mauritanians.
Convictions are rare, and the country has jailed more anti-slavery activists than slave owners, rights groups say.
Habi Mint Rabah was saved thanks to her brother Bilal Ould Rabah, who had managed to free himself. He alerted human rights organisations and the IRA movement, whose mobilisation resulted in the release of his sister after more than 35 years in bondage.
"She is a victim of slavery who we freed. She joined us, is militant, and will prove herself against the dominant pro-slavery group in the coming parliament," says IRA's President Biram Dah Abeid.
The European Union has announced it is doubling its financial contribution to a security force mounted by the five countries of the Sahel region - Burkina Faso, Chad, Mali, Mauritania and Niger.
The EU's foreign policy chief, Federica Mogherini, promised the extra $61m (£44m) at the start of an international donor conference in Brussels attended by 50 nations.
She also highlighted the need for development funds in the region, where the EU is investing nearly $10bn in its seven-year plan until 2020.
She said it was important for the region and also for Europe.
BBC Africa security correspondent
Heads of state from Burkina Faso, Chad, Mauritania, Mali and Niger are meeting at this year’s G5 Sahel Summit in Niamey, Niger's capital.
While the operation of their joint regional counter terrorism force will be top of the agenda, they’ll also discuss other issues including regional development and the rotational presidency of the grouping, which is currently held by Niger.
The $500m (£360m) budget target for the G5 Sahel Force has nearly been met, although it is still not clear how this will be spent.
The force carried out its first operation last October and its second last month.
It is expected to collaborate with French and UN forces in the region to try and bring stability in the wake of instability from jihadi militants in the Sahel.