Let's say the Netherlands wants to fish in the EEZ of Sierra Leone. Is the EU as body involved in this at all? Or does the Netherlands negotiate fishing rights with the non-EU country in question, possibly through an RFMO? If the EU does get involved, does it divvy up whatever is negotiated with the non-EU country among (several) EU member states, according to some predetermined method?
It's part of the responsibilities of the EU Commission (source):
EU Sustainable Fisheries Partnership Agreements ... with non-EU countries are negotiated and concluded by the Commission on behalf of the EU. They allow EU vessels to fish for surplus stocks in the country's exclusive economic zone (EEZ), in a legally regulated environment. These agreements also focus on resource conservation and environmental sustainability, ensuring that all EU vessels are subject to the same rules of control and transparency. At the same time, a clause concerning respect for human rights has been included in all protocols to fisheries agreements.
The EU has several of these agreements in place:
As for the methodologies:
There are two main types of agreements:
Tuna agreements – allow EU vessels to pursue migrating tuna stocks as they move along the shores of Africa and through the Indian Ocean.
Mixed agreements – provide access to a wide range of fish stocks in the partner country's exclusive economic zone.
In exchange, the EU pays the partner countries a financial contribution composed of 2 distinct parts:
access rights to the EEZ
sectorial support which aims to promote sustainable fisheries development in the partner countries, by strengthening their administrative and scientific capacity through a focus on sustainable fisheries management, monitoring, control and surveillance
And regarding the share by member state (source):
The EU also sets annual catch limits for most commercial fish stocks. These are also called total allowable catches (TACs) or fishing opportunities. Each TAC is shared among the EU member states through national quotas. Individual member states are responsible for ensuring that their quotas are not overfished.
For fish stocks that are shared and jointly managed with non-EU countries, the TACs agreed at EU level have to be in line with the results of recurring consultations with those non-EU countries. These consultations are based on international agreements on cooperation in fisheries management.