There are four items for the agenda - in this order: stickleback, HELCOM BSAP, harbour porpoise, and seals
The REMINDER invitation (sent 21.08.20)
Revised 080920 agenda
FINAL report from meeting 
Presentation by Ulvi Päädam on stickleback
Presentation by Jens Olsson on stickleback
Presentation by Markus Helavuori on HELCOM and update of Baltic Sea Action Plan
Presentation by Henn Ojaveer on the ICES advice on harbour porpoise
Note for agenda item 3 (stickleback)
Contribution from Algirdas Ausra (Confederation Fishermen and Fish Processors West Lithuania)
Note for agenda item 4 (HELCOM and BSAP update) - updated note 15.9.20
Excel table with proposals  - sent 15.9.20
As far as I can see, there are two proposals where the links don't work. These are:
Development of alternative fishing gear to replace gillnets
Establish an effectively and equitably managed, ecologically representative and well-connected system of highly protected marine protected areas (MPAs), covering a minimum of 30 % of the Baltic Sea area by 2030.
All the proposed actions listed by HELCOM are here 
Note for agenda item 6 (Harbour porpoise)
BALTFISH Presidency draft Joint Recommendation on harbour porpoise
BALTFISH Revised draft Joint Recommendation on harbour porpoise REV 2020
From the Secretariat What has changed
Documentation sent to the Secretariat:
Feeding ecology of pelagic fish species in the Gulf of Riga (Baltic Sea): the importance of changes in the zooplankton community
Stickleback increase in the Baltic Sea - A thorny issue for coastal predatory fish
Declining coastal piscivore populations in the Baltic Sea: Where and when do
sticklebacks matter?

Seasonal dynamics in the diet of pelagic fish species in the southwest Baltic Proper
Morphological divergence of three-spined stickleback in the Baltic Sea -Implications for stock identification
Predator–prey role reversal may impair the recovery of declining pike populations
From the European Anglers Alliance: Recreational Angling in Marine Protected Areas: EAA position paper  
EAA position statement on the rebuilding of the European eel stock (including minority statement from DAFV)
Article from Science on synthetic harbour porpoise communication signals Jérôme Chladek et al