WADA-SD-CAN: DESCRIPTOR 2. Once introduced, alien species are components of ecosystems that can be evaluated by means of condition indicators, but in terms of good environmental status they should be considered as a pressure on native ecosystems. Thus, what will guarantee good environmental status in relation to this descriptor will be the absence of pressure, that is, the absence of alien species. However, given the irreversibility of the great majority of processes of establishment of alignant species, it is not possible to consider the BEA as the absence of alignant species. For this reason, the criteria associated with the descriptor are oriented on the one hand towards maintaining the status quo, that is to say, to reducing the rate of new primary introductions and limiting the expansion of those already established, which reduces the possibility of negative impacts, and on the other hand refers to the direct evaluation of these impacts. For the same reason as mentioned above regarding the irreversibility of the invasions, these impact indicators should give an account of the temporal evolution of the degree of negative impact, and consider that the BEA is achieved by reducing the rate of increase of these impacts.
br />According to what was explained in the previous section, in the sense that alien species are in fact a pressure that threatens the good environmental status of ecosystems, the BEA should not be defined as the result of a particular state of alien species, but rather as a function of the state of native biotas. In fact, the BEA in relation to descriptor 2 consists of the achievement of the BEA with respect to descriptors 1 (biodiversity), 3 (commercial species), 4 (food webs) and 6 (integrity of the bottoms). In addition, taking into account the characteristic of pressure on the marine environment that involves the algae species, a second characteristic of the BEA can be established in reference to the minimization of pressures. Therefore, the Good Environmental Status of descriptor 2 is defined in these two facets
AMA-ES-SD-CAN: DESCRIPTOR 4. Due to the scarcity of information on this descriptor in the Canary Islands Marine Demarcation, it has been decided to define Good Environmental Status in a qualitative way.
AMA-ES-SD-CAN: DESCRIPTOR 5. According to the DMEM, Good Environmental Status (GES) with respect to eutrophication is achieved when “human-induced eutrophication is minimized, especially adverse effects such as loss of biodiversity, ecosystem degradation, massive algae blooms and oxygen deficit in deep waters”. It is clear that minimizing the effects of eutrophication occurs when the impact of nutrients released from ocean sources remains below a threshold that does not produce effects on the marine environment. This maximum threshold will depend on the characteristics of each area (hydrographic conditions, currents, ecosystem structure, etc.). Therefore, it should be defined specifically for each area of study within the Demarcation. In the evaluation presented in the previous section, areas of relatively homogeneous productivity have been defined, which are therefore expected to present a high degree of sensitivity to nutrient enrichment.
In practice, it is not possible to quantitatively define, with the available data, that maximum threshold of nutrient load. Alternatively, we propose to evaluate the eutrophication in the coastal areas of the Demarcation by comparison with the open sea areas. According to this evaluation, it is possible to define a BEA for each of the indicators (or group of indicators) in the terms shown in Table 5.6. As can be seen, the definition includes two complementary criteria for defining the EA for each group of indicators: time trends and reference values.
The indicators of Descriptor 5 are hierarchically structured, so that only if a trend towards an increase in nutrient concentration is detected, not linked to hydrological variability, quantifiable effects on the concentration of chlorophyll or phytoplankton communities attributable to contamination can be expected. However, similarly to what was done for Criterion 3.1, a definition of the BEA can be suggested for Criterion 3.2:
"The BEA corresponds to SSB/SSBMSY being ≥1 for at least 50% of the stocks and not {;0. 6 for no stock."
The value 0.6 is the result of 1/1.6, being 1.6 the value used in the definition of the BEA for Criterion 3. 1.
In an analogous way, the current state in relation to the BEA could be measured in a scale of 0 to 1, with the value 0 corresponding to the worst situation and 1 corresponding to the BEA, by means of the formula:
max[ 0 , 1 – proportion of red stocks – max{0, 0. 5 – proportion of stocks in green} When there is no SSBMSY (or precautionary biomass) reference point, it is not possible to work on the basis of columns 1 & 2 of Table 3.4. In that case, it would be possible to work with columns 3 and 4 of the table, which use the average of the biomass over the whole period,7)-T(T,B, instead of BMSY. The advantages of working with columns 3 and 4 over using columns 1 and 2 are that all stocks with main or secondary indicators are considered in the calculation and that the interpretation is consistent among them. However, it is very important to note that a value of 1 in this case would not necessarily correspond to the BEA, since the analysis is not based on BMSY but on the historical values of the B.
AMA-ES-SD-CAN: DESCRIPTOR 6
In none of the habitats is currently available adequate information on its extent and / or status. The spatial and methodological limitations do not allow to define at this time the BEA (Good Environmental Status) of the habitats as a quantitative value or point. Therefore, the definition of Good Environmental Status should not be the reference level established in the evaluation of the state, but a positive trend towards that level or stability, since in many cases the reference level is impossible to achieve (loss of irreversible habitat, high social costs, long-term time scale of recovery processes, etc.). On the other hand, the concept of Good Environmental Status must take into account the sustainable use of the seas and a level of human activity that is compatible with the conservation of marine ecosystems, in accordance with the ecosystem approach. Therefore, the BEA cannot be assimilated to the reference level, but must take into consideration other factors.

In this case it is not possible to define a BEA (in a quantitative way) for this demarcation due to the lack of information that we currently have about the area. In case of having the same, the good environmental status (BEA) that would be proposed for this descriptor should be adjusted to the international criteria of environmental quality derived either from the legislation in force or from those proposed at a regional level by international agreements. Therefore, the BEA would be fulfilled if these reference values (derived for the appropriate species) were not exceeded in a large majority of cases. Therefore, an area would present a Good Environmental Status if it does not exceed the levels established by the competent authorities and regional bodies in a large majority of its samples and when the temporal trends are decreasing or remain stable (in those cases where the levels detected are very close to the baseline).

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INDICATOR 8.1.1. CONCENTRATION OF CONTAMINANTS: The evaluation of contaminant concentration data requires the use of reference levels, both to identify areas of low anthropogenic influence with concentrations close to baseline and for those areas where concentrations may cause adverse effects on the ecosystem. Thus, two transition values T0 and T1 are established, where - Values T1 mean that the concentration of the hazardous substance may pose a risk to the environment and the species that inhabit it. It is therefore necessary to establish these two threshold values. On the one hand it is important to know the natural concentrations of contaminants naturally present in the marine environment (metals and PAHs) in order to make a good estimate of the level of contamination by a given element. The natural levels are related to the chemical or geochemical nature of the areas studied. However, it is very difficult to determine the background level, natural concentration or base concentration, since nowadays it is practically impossible to find places that have not been affected by human activities. Currently, there are no universally accepted values, and there is not even consensus on the best methodologies to determine them. In this sense, as a T0 threshold, the BAC (Background Assessment Criteria) defined within the ICES/OSPAR working groups will be used (Table 8.1 of document "IV_D8Canarias.pdf"). These are statistical assessment tools that allow the identification of those values that are close to baseline concentrations (those that would exist in pristine areas, far from pollution sources) (OSPAR, 2008). On the other hand, for the case of the threshold value T1 there are different approaches. On the one hand, Directive 2000/60/EC establishes quality criteria for assessing concentrations of pollutants in inland and coastal waters, the Environmental Quality Standards (EQS) (Directive 2008/105/EC). In the case of concentrations of pollutants in sediments and biota, the quality standards used, where possible, correspond to the environmental assessment criteria (Environmental Assessment Criteria, EAC), agreed by experts in the field of working groups ICES and OSPAR (Table 8.1.). These EACs are defined as assessment tools that represent the concentration of pollutant in sediment or biota below which chronic effects on marine species, including the most sensitive ones, are not expected. In this sense they are related to the EQS, applied to the concentration in water of the Directive 2008/105/EC. Although it is expected that concentrations of contaminants below the EACs do not give rise to unacceptable biological effects, it is necessary to remember that their use in specific cases requires expert judgement. In addition, these CAEs do not take into account specific long-term effects, such as carcinogenicity, genotoxicity and/or reproductive disruption due to hormonal imbalances, nor do they take into account the combined toxicity of the contaminants (Webster et al., 2009). During the preparation of the evaluation for the 2010 QSR it was found that CADs had not been defined for all matrices/contaminants and/or that in some cases they were not usable. In the case of the Canary Islands Demarcation, the available data are very scarce and do not come from established monitoring programs with proven quality. Furthermore, the species studied in these publications do not always coincide with those for which there are established quality criteria. Therefore, in most cases it will not be possible to make comparisons with the evaluation criteria. Another group of environmental criteria available is the ERL (Effects Range Low) (Table 8.1). These are sediment quality criteria developed by the United States Environmental Protection Agency (US EPA) to protect organisms from the adverse effects of contaminants. ERL is defined as the 10th percentile of sediment concentration data associated with biological effects. Concentrations below ERL rarely cause biological effects and, although not equivalent to ACE, are an interim solution while ACE is not available for the contaminants used in this report. To carry out the evaluation of the concentrations of metals in biota there are no EACs defined in OSPAR, nor alternatives defined on the basis of toxicological criteria that can be used. In this case, and knowing that this is a compromise solution, one could choose, as was done in the QSR 2010, to compare the concentrations of contaminants with the maximum values allowed in fishery products to protect human health, defined in Regulation (EC) No 1881/2006 (and subsequent amendments and modifications). INDICATOR 8.2.1. EFFECTS OF CONTAMINANTS OSPAR (OSPAR, 2007a), in cooperation with ICES (ICES, 2011b), has established assessment criteria for a number of biological effects techniques. Within these criteria, the range of basal response (RRB) corresponds to values equal to or less than the 90th percentile, derived from responses in organisms inhabiting clean sites or sites minimally impacted by chemical contaminants. The range of elevated response (RRE) is the expected response in organisms that inhabit sites where the impact of chemical contaminants is possible [>RRRB and RRRB × 10]. These criteria should be considered provisional and will need to be revised when more data become available. One of the most widely developed techniques is the measurement of imposex, caused by tributyltin (TBT) in marine gastropods. OSPAR has established an ecological quality objective (EcoQO) for several gastropod species (Nucella sp., Littorina sp., Nassarius sp., Buccinum sp. and Neptunea sp.), according to which, the average level of imposex in a sample of at least 10 female gastropods, should be consistent with exposure to TBT concentrations below the EAC value for this compound (OSPAR, 2007b).

Of the different pollutants that enter the marine environment, those that are being considered under the OSPAR Convention will be selected. The basis for the knowledge of the environmental concentrations of these pollutants, and therefore for the evaluation of the progress towards good environmental status, are the marine pollution monitoring programmes, in which repeated measurements are carried out in key locations, for which there is a long time series of data. Effects of pollutants: The effects of the pollution on the components of the ecosystems of interest will be evaluated, taking into account the selected biological processes and the taxonomic groups where a cause/effect relationship has been established and needs to be monitored (indicator 8.2.1). The frequency, origin (where possible), extent of events that cause significant acute pollution (e.g. oil spills), and the impact on biota physically affected by this type of pollution should be determined (indicator 8.2.2). The assessment of the impact of contaminants on organisms requires consideration of effects at different levels of biological organization. The methods selected for the evaluation are among those recommended by the ICES working groups as appropriate for use in marine pollution monitoring programs. CRITERION 8.1. CONCENTRATION OF POLLUTANTS: The parameters selected for the evaluation of the current state in the North Atlantic demarcation are shown in Table 8.2 (Document IV_D8 Canary Islands). Two environmental matrices have been selected (surface sediments and wild mussels) which have been evaluated in a standardized way in the environmental monitoring programs that the IEO has been carrying out to date. These parameters and matrices are also the most used within the existing national environmental monitoring programs in Europe, and are recommended by the regional program CEMP (OSPAR). In the case of the levels of pollutants in coastal water, the available information sent by the Ministry of Agriculture, Food and Environment will be used for the compliance of the WFD. Regarding the SEDIMENT MATRIX: Sediments are preferable to water samples as a matrix for monitoring environmental quality, since the concentrations of contaminants in them are much higher and less variable in time and space, reflecting in an integrated way the state of contamination of an area. Most of the chemical compounds of anthropogenic origin that are introduced in the marine environment accumulate in the sedimentary matrix, but these not only act as a reservoir for the contaminants, but also serve as a source of toxics for the marine fauna. For these reasons, this matrix is the object of study in marine pollution monitoring and control programs. It is usually recommended to analyze the fraction below 2 mm in spatial distribution studies. The reason is that this fraction, also called total fraction, practically includes the sediment to which only the largest solid materials have been removed and, therefore, gives an idea of the real content of contaminant per unit weight of sediment. For this reason, concentrations of contaminants in the total fraction are considered to be a significant and useful data from an ecological and ecotoxicological point of view, while data on concentrations in specific fractions have a much less direct interpretation, and much more complex. BIOTIC MATRIX: One of the most widely used organisms worldwide as a biological tool in pollution monitoring programs, to reveal geographic patterns and to identify temporal trends in coastal pollution, is the mussel. These are ubiquitous, abundant and sedentary organisms with a relatively long life cycle. They resist conditions of hypoxia, environmental stress and pollution. They are large filters that apparently lack a good system of mono-oxygenases, so they accumulate high concentrations of pollutants. They are also consumed by organisms of higher trophic levels. For all these reasons, since the early 90's, the Spanish Institute of Oceanography (IEO) has been using the wild mussel as an indicator of pollution since it allows the identification of variations in chemical pollutants along the coast, and contributes to the observation of coastal pollution trends. With the same objective, and following the guidelines of the JAMP, studies have also begun on a demersal species, hake (Merluccius merluccius), however, the information available to date is very scarce so it is not analyzed in this initial assessment. In the case of mussels, since sampling is done once a year and its objective is to minimize natural variability, a sampling strategy was designed with a series of variables that are met over the years: collection at low tide, wide range of mussel sizes, sufficient number of individuals of all sizes, fixed sampling points throughout the years and sampling always at the same time of year (October-November), since it has been observed that contaminant concentrations vary throughout the year coinciding with variations in the biological cycle. Following the OSPAR-JAMP guidelines, the time selected for sampling corresponds to the period in which these organisms are in a more stable physiological state (OSPAR, 1999). CRITERION 8.2. EFFECTS OF CONTAMINANTS: For the evaluation of the current state in the North Atlantic demarcation, a series of biological responses have been selected that have been used in various campaigns to study the effects of chemical contamination (Table 8.3). These biological responses present, in general, a greater validation in field studies, and are widely used in the existing national environmental monitoring programs in Europe, being recommended in the regional programs of MED POL and OSPAR/CEMP. Both the indicator species and the selected variables vary from one district to another, depending on the biogeographical singularities and the recommendations of the regional conventions.