I have copied the relevant section that relates to angling for clear guidance. I have read a lot of speculation regarding regulations but from what I can see its fairly clear. You can go fishing providing social distance is maintained. Competitive angling and charter boat fishing is not presently on the agenda and suspect it will be July at the earliest before this returns. It would be good if tackle shops could open but my interpretation is that it will be June before this happens.
I confess that I have not read all fifty pages of the report that can reviewed via the below link.
SAGE advise that the risk of infection outside is significantly lower than inside, so the Government is updating the rules so that, as well as exercise, people can also now spend time outdoors subject to: not meeting up with any more than one person from outside your household; continued compliance with social distancing guidelines to remain two metres (6ft) away from people outside your household; good hand hygiene, particularly with respect to shared surfaces; and those responsible for public places being able to put appropriate measures in place to follow the new COVID-19 secure guidance.
People may exercise outside as many times each day as they wish. For example, this would include angling and tennis. You will still not be able to use areas like playgrounds, outdoor gyms or ticketed outdoor leisure venues, where there is a higher risk of close contact and touching surfaces. You can only exercise with up to one person from outside your household – this means you should not play team sports, except with members of your own household.
People may drive to outdoor open spaces irrespective of distance, so long as they respect social distancing guidance while they are there, because this does not involve contact with people outside your household.
When travelling to outdoor spaces, it is important that people respect the rules in Scotland, Wales and Northern Ireland and do not travel to different parts of the UKwhere it would be inconsistent with guidance or regulations issued by the relevant devolved administration.
These measures may come with some risk; it is important that everyone continues to act responsibly, as the large majority have done to date. The infection rate will increase if people begin to break these rules and, for example, mix in groups in parks, which will trigger the need for further restrictions.