This was the first interim year for the multi-annual Terms of References (ToRs) for the Working Group on Biological Parameters (WGBIOP). ToR a was the consolidation of the WGBIOP itself, ToRs b, c and e were dealing with the development of a quality assured assessment of new and existing biological parameters for both single-and in-tegrated stock assessment. ToRs d, f and g were the generic ToRs for the group han-dling the reviewing of calibration exercises on biological parameters, their outcomes and recommendations for such actions, including a continuous development of tools for facilitating such calibrations. WGBIOP addressed ToR a) both as a general plan for the group but also by agreeing on specific plans for each ToR. In terms of the remits of the WGBIOP, it was concluded that the group will not only focus on existing biological parameters but also on accu-racy in derived life-history parameters estimation which may support stock assess-ment; both single-stock and integrated ecosystem assessments. Given this rather ambitious remit, the group decided to focus the first 3-year period on defining new (for assessments) and existing biological parameters (ToR b) , their quality in terms of sam-pling and estimation (ToR c) and how these may be integrated in the general bench-mark process in ICES (ToR e). Concerning the generic ToRs (d, f and g) it was decided to follow the outlined procedure in the ToRs (i.e. continue the work on quality assur-ance of biological parameters through workshops and calibrations as previously done in PGCCDBS), and in addition have a developmental side to them. WGBIOP decided to expand the workshop/exchange review to include under the WGBIOP remits also the work performed on ichthyology, fish egg production and ichthyoplankton related issues. Discussions related to ToR b led to a specification of the broad groups of new and ex-isting biological parameters that are emerging as critical components of state-of-the-art assessment. A descriptive database was initiated including details of the necessary data providing information on the particular parameter, the types of species/ecosystems for which they are most useful, the type of stock/ecosystem models that they are typically used in, and examples of where they have been used before. The discussions on this ToR led to a draft of a “roadmap” that can guide end-users on the data collection, po-tential usefulness, and typical approaches employed when incorporating this new bi-ological information into assessment. WGBIOP addressed ToRs c and e in combination and ended up merging these into one single ToR: “Evaluation of quality of biological parameters: issues, quality indicators and guidelines”. The discussions under this new ToR were very fruitful and led to a thorough review of the issues regarding biological parameters. Issues put forward by the assessment WGs for benchmark stocks were evaluated (‘top–down’ approach) and, as an example, the WGNSSK 2015 report was screened for issues (‘bottom–up’ ap-proach). This evaluation focused on existing biological parameters already included in assessments (e.g. age, maturity, natural mortality). New biological parameters from this review were discussed under ToR b. The development of Quality Indicators was initiated for existing biological parameters.