ALBERT

Description: The ICES Workshop on ICES reference points (WKREF2) was tasked review the WKREF1 report and based on the outcome develop updated guidelines for the ICES reference points system and recommendations for ACOM consideration. The WKREF1 report has suggested 5 key recom- mendations to simplify and harmonise the ICES reference points framework representing a ma- jor change to the current guidelines. At WKREF2, we detailed discussions and four key concerns were raised about the proposed approach. The first related to the simplification of rules to define Blim. Around two thirds of category 1 stocks would end up as WKREF1 “Blim Type 2” where Blim would be set as a fraction of B0. The Allee effect or “depensation” maybe more important than previously thought and should be furthered explored for ICES stocks since it has important consequences for Blim. A number of challenges and issues around defining Blim using the current guidelines were documented. Some suggestions on improvement criteria were discussed including using classifiers to define spas- modic stocks and using change point algorithms to address non-stationary productivity regimes. However, further work is need to make these approaches operational and there was no consen- sus that the WKREF1 Blim types should replace the current guidelines. WKREF1 recommended that the FMSY proxy should be based on a biological proxies and should be less than the deterministic FMSY. It was pointed out that the stochastic FMSY estimated in EqSim for example, is lower than the deterministic FMSY and that the current guidelines ensure that the FMSY should not pose a more than 5% risk to Blim. A large amount of work described in WD 1 was carried out to develop an MSE framework to consistency and robustness test a candidate refer- ence point system for North East Atlantic stocks. However, WKREF2 recommended that further work needs to be carried out to condition and test the simulation framework before the conclu- sions could be adopted by ICES and incorporated into the guidelines. A number of considerations for defining MSY related reference points were discussed including using model validation and prediction skill to ensure that ICES provide robust and credible ad- vice. There is evidence that density dependence (DD) is important in the majority of ICES stocks (68% in recruitment and 54% in growth). The correct prediction of the shape and strength of density-dependence in productivity is key to predicting future stock development and providing the best possible long-term fisheries management advice. A suggested approach to use surplus production models (SPMs) to account for DD in FMSY was suggested and discussed but there was no consensus on whether that approach was appropriate. There was consensus that the FECO approach as a means of adapting target fishing mortality to medium-term changes in productiv- ity should be included in the guidelines subject to a benchmark and ACOM approval. While WKREF1 and 2 focused mainly on Category 1 stocks ToR c) called for a “simplified and harmonised set of guidelines for estimating MSY and precautionary reference points applicable in the advice framework across various ICES stock categories.” Ideally the ICES assessment cat- egories should provide equivalent risk across all stocks. This issue was discussed but no recom- mendations emerged. There was no consensus a revised reference point framework was proposed at WKREF2. How- ever, it was agreed that it should be presented here for further discussion at ACOM and other fora. The key feature of the suggested approach is that the stock status evaluation is treated in- dependent of the Advice Rule (AR). The main feature of the system is that the biomass trigger is not linked to a stock status evaluation, it is linked to the expected biomass when fishing at the target fishing mortality, in contrast to the current ICES approach. It also entailed that FMSY would also become an upper limit of fishing mortality and that the advised fishing mortality would be set at or lower than that level. WKREF2 did not discuss what to do in situations where SSB〈 Blim or alternative forms of HCR for the advice rule. Building community understanding and con- sensus around simplified and harmonised guidelines has yet to be achieved. A further workshop WKREF3 will be required to achieve that aim. The report includes 6 recommendations for ACOM consideration.

Description: ICES

Description: The main objective of the workshop was to review the recommendations of WKREF1 and con- sider how these might feed into a new reference points framework and guidelines for ICES. There were a number of presentations on the wider issues of best practice for reference points, the Allee effect, density dependence and the WKIRISH approach. The starting point was to try and develop a set of simplified and harmonised guidelines based on the WKREF1 report rather than evolving the current guidelines to include the WKREF1 conclusions. A key aspect of the meeting was to allow for discussions in order to build a shared understanding of the strengths and weakness of the current framework and of the new framework emerging from WKREF1.

Description: Published

Description: Non Refereed

Description: Among the approximately 10,000 beneficial species of marine phytoplankton in the world’s oceans today, some 200 taxa can harm human society through the production of toxins that threaten seafood security and human health. These toxins are also responsible for wild or aquaculture fish-kills, may interfere with recreation-al use of coastal or inland waters, or cause economic losses. Non-toxic microalgae attaining high biomass can also cause Harmful Algal Blooms (HABs) by producing seawater discolorations, anoxia or mucilage that negatively affect the environment and human activities. The most frequently asked questions about harmful algal blooms are if they are increasing and expand-ing worldwide, and what are the mechanisms behind this perceived escalation. These questions have been addressed in several review papers concerning HAB trends at various scales, where evidences of expansion, intensification and increased impacts of harmful algal blooms have been gathered from a selection of examples that have gained high prominence in the scientific world and in society 1,2,3,4. Eutrophication, human-mediated introduction of alien harmful species, climatic variability, and aquaculture have all been mentioned as possible causes of HAB trends at various spatial and temporal scales 5,6. Over the last 40 years, the capacity and monitoring efforts to detect harmful species and harmful events have significantly increased, thus increasing the reporting of harmful events across the world’s seas. The resulting information is mostly scattered in the ever growing literature, with data from statutory monitoring programs often not published in peer review journals, while an extensive and detailed overview of the huge amount of information on harmful species, their spatial and temporal distribution and the trends of HABs they have caused has never been attempted so far. This lack of a synthesis of the relevant data has hampered a sound global assessment of the present status of phenomena related to harmful algae. Following the lead of the International Panel for Climate Change (IPCC) consensus reporting mechanism, and to complement the World Ocean Assessment, the need has been expressed for a Global HAB Status Report compiling an overview of Harmful Algal Bloom events and their societal impacts; providing a worldwide appraisal of the occurrence of toxin-producing microalgae; aimed towards the long term goal of assessing the status and probability of change in HAB frequencies, intensities, and range resulting from environmental changes at the local and global scale. This initiative was launched in April 2013 in Paris by the IOC Intergovernmental Panel on HABs (IOC/IPHAB), and has been pursued with the support of the Government of Flanders and hosted within the IOC International Oceanographic Date Exchange Programme (IODE) in partnership with ICES, PICES and IAEA. As a first step towards a global HAB status assessment, a Special Issue of the journal Harmful Algae (vol. 102, February 2021) has been published comprising 12 papers 7-18 each presenting an overview of toxic and non-toxic HABs in a specific area of the world’s seas. The regional overviews build on existing literature and exploit the information gathered in two relevant data-bases, both incorporated into the Ocean Biodiversity Information System (OBIS).

Description: Government of Flanders

Description: OPENASFA INPUT This Global HAB Status Report summary was prepared based on the special issue Global HAB Status reporting, vol. 102 (Feb. 2021) of the Harmful Algae (Elsevier Journal)

Description: Published

Description: Refereed

Description: The Marine Strategy Framework Directive (MSFD) requires Member States to achieve good environmental status (GES) across their marine waters. The EU have requested ICES to advise on methods for assessing adverse effects on seabed habitats, through selection of relevant indicators for the assessment of benthic habitats and seafloor integrity and associated threshold values for GES in relation to Descriptor 6 – Seabed integrity under the MFSD. Two sets of criteria were developed to evaluate indicators and thresholds respectively for evaluation of suitability for assessing GES. 16 indicator and 12 threshold criteria were compiled and weighted by importance. The criteria were designed for evaluation at a subregional or regional level. The scoring for these criteria is meant as a guidance when choosing indicators and thresholds, so failure to meet one criterion will not necessarily prevent the use of the indicator or thresh-old in an assessment. The framework was evaluated for 6 indicators and for 11 methods for setting thresholds. The criteria were found to be useful for evaluation both indicators and thresholds. The process works most consistently when there are experts in the group on both the criteria themselves and on the indicators and thresholds. The MFSD Descriptor 6 determination of GES needs both a quality threshold (when are seabed habitats in a good state in a specific location) and an extent threshold (proportion of the assessment area that needs to have seabed habitats in good state). Eleven different methods for setting thresholds were identified, of which more are suitable for setting quality than for extent thresholds. Preferred methods identified an ecologically-motivated difference between a good and de-graded state, rather than another transition. Quality thresholds based on the lower boundary of the range of natural variation were considered most promising. This approach can be used for most, but not all, indicators. The WK collated a standardized dataset to test the specificity, sensitivity and/or responsiveness of sampling-based benthic indicators to pressure gradients for evaluation by WKBENTH3. Risk-based methods will be evaluated as maps and by scored sensitivity and impact score per MSFD habitat type and subdivision. Participants provided input into the selection of indicators for the compilation of indicators. A template was developed for documenting the characteristics of each indicator to facilitate the evaluation of the indicators.

Description: ICES

Description: Published

Description: Non Refereed