Issues surrounding a fishing conservation plan that has also become a big earner is the key topic at a meeting this week of the Parties to the Nauru Agreement in Tuvalu.Tuvalu's permanent secretary in the Ministry of Natural Resources, Kakee Kaitu, says a recent review of the Vessel Day Scheme, or VDS, offered thought provoking challenges for the eight member countries.He says all the member nations will benefit from a strengthened VDS, without loopholes and with full compliance by participants, but he says it may be necessary to make concessions to achieve that.And the members, Papua New Guinea, Nauru, the Marshall Islands, Kiribati, the Federated States of Micronesia, Palau, and Solomon Islands, will also consider a request from the Cook Islands that it join the PNA's vessel day scheme.Tokelau signed up to the VDS two years ago.