État chimique des eaux littorales en 2015, selon la Directive-cadre sur l’eau

The Water Framework Directive (WFD) defines two types of coastal water bodies: coastal waters and transitional waters.

In 2015, 65% of the 273 coastal water bodies are in good chemical status: 73% of 179 coastal waters and 51% of 94 transitional waters.

The share of coastal water bodies in poor chemical status is 20%. This concerns 16 coastal waters (9%) and 38 transitional waters (40%). Most of these water bodies are located in the districts: Seine and Normandy coastal watercourses, Rhone and Mediterranean coastal watercourses and Corsica watercourses.

About forty coastal water bodies (15%) are in unknown chemical status (or insufficient information to assign a status). Coastal waters with unknown status are mainly located in Reunion and Martinique. Transitional water bodies in this situation are found in Adour-Garonne, Guyana, Martinique and Seine and Normandy coastal watercourses.

In 2015, 73% of coastal waters are in good chemical status. This is 20 percentage points higher than for transitional water bodies, for which one water body in two is in this situation. For all surface water bodies (11,414), combining all water categories (rivers, lakes, lagoons, estuaries and coastal seas), the share in good chemical status is 63%.

Conversely, only 9% of coastal waters are in poor chemical status, while more than 40% of transitional waters are in this situation, or 4.5 times more than coastal waters. For all surface waters, the share of water bodies in poor status is 16%.

Finally, 15% of coastal water bodies are in unknown chemical status (insufficient information to assign a status). The number of water bodies in this status has significantly decreased between the last two evaluations (2013 status report and 2015 assessment), declining from 26 to 18% for coastal waters and from 12 to 9% for transitional waters. This decrease is explained in particular by improved knowledge and data acquisition of measured pollutant substance concentrations (improved analysis techniques).

The Water Framework Directive recommends working at the scale of "river basin districts". In total, 14 river basin districts are established in France: 9 in mainland France and 5 for overseas territories, one per overseas department. In mainland France, only 6 districts have a coastal frontage.

• The chemical status of water bodies varies from one district to another. • For water bodies whose status could be assessed, the share of coastal waters in good chemical status is always greater than that of waters in poor status. Thus, all coastal waters in the districts of Scheldt (5), Loire (39), Adour-Garonne (10), Mayotte (17) and Guyana (1), representing a significant portion of French coasts, are in good chemical status. • Sixteen coastal water bodies are in poor chemical status. These are: • five water bodies in the Continental Mediterranean district: Frontignan - Espiguette Point, Gulf of Fos, Small Marseille Anchorage, Villefranche Anchorage and Monte Carlo - Italian Border in Alpes-Maritimes; • five water bodies in the Seine district: Bessin Coast in Normandy, Côte Fleurie, Le Havre-Antifer, Pays de Caux south and Pays de Caux north; • two water bodies in Corsica: Cape east of Corsica and southwest coast of Corsica; • four in Guadeloupe: Petit Cul de sac, Pointe du vieux fort-Sainte Marie, Port Louis-Pointe Madame (Grand Cul de Sac marin) and Saint Martin (French part). • Coastal water bodies in unknown status are mainly located overseas: Martinique and Reunion.

• Overall, the situation of transitional water bodies is worse than that of coastal waters. • In mainland France, the share of transitional water bodies in poor chemical status exceeds that of waters in good status for the districts of Seine (75%), Continental Mediterranean (59%) and for all water bodies in Corsica. • Conversely, 75% or more of water bodies in the Loire and Scheldt districts are in good chemical status. • Of the 94 transitional water bodies, 38 are in poor chemical status (40%). Namely: • the port of Dunkerque (Scheldt district); • the Gironde estuary (Adour-Garonne district); • sixteen water bodies in Continental Mediterranean: Canet pond, Salses-Leucate pond, Palme pond, Bages-Sigean and Campignol ponds in the Narbonnais pond complex, Vendres pond, Thau pond, l'Or pond, east and west Palavasian ponds, Small Camargue Marette, Camargue Vaccarès Complex, Palissade ponds and Berre Ponds (Grand Etang, Vaïne and Bolmon); • four lagoons in Corsica: Biguglia pond, Diana and Urbino ponds in the eastern plain and Palu pond; • five water bodies in the Loire district: Aber Benoît, Aulne and Elorn (in Brest roadstead), Goyen (south of Cap Sizun) and Loire; • six water bodies in the Seine district: upstream, middle and downstream Seine estuary, bottom of Mont Saint Michel and Veys bays, Risle from Borbie confluence to Seine confluence; • five Guyana estuaries: Maroni, Kourou, Cayenne, Mahury and Approuague. • Transitional water bodies in unknown status are located in Adour-Garonne, Guyana, Martinique and Seine.

• The evaluation of the chemical status of a water body is based on the comparison between: • measurements of the concentration of chemical substances/substance families within the water body and; • threshold concentrations determined in water or biota (environmental quality standards (EQS)). • Thus, a water body is considered in poor status if the concentration of at least one substance exceeds the environmental quality standard. • In total, 41 priority substances/substance families are monitored including: 4 with restricted use, 13 banned, and 3 with no use in France.

• Among the monitored substances are: • heavy metals and their compounds (cadmium, lead, mercury, nickel); • pesticides: herbicides (alachlor, atrazine, simazine, diuron, isoproturon, trifluralin), insecticides (chlorpyrifos, chlorfenvinphos, endosulfan, organochlorine pesticides: aldrin, dieldrin, endrin, isodrin), fungicide (pentachlorobenzene); • ubiquitous substances: polycyclic aromatic hydrocarbons (PAH), tributyltin compounds, polybrominated diphenyl ethers (PBDE); • other pollutants: dichlorodiphenyltrichloroethane (DDT) and derivatives, alkylphenols, dioxins, di(2-ethylhexyl)-phthalate (DEHP)…

• Among the 41 priority substances/substance families monitored, 14 cause the non-achievement of good chemical status in coastal waters. • For coastal water bodies, the main pollutants causing water body downgrading are: tributyltin cation (tributyltins are biocides widely used in antifouling paints on boat hulls in the 1970s and prohibited for application on ships since 2003), hexachlorocyclohexane and endosulfan. • The main substances downgrading transitional waters are: hexachlorocyclohexane, organochlorine pesticides (aldrin, dieldrin, endrin, isodrin), endosulfan and the sum of PAH Benzo(g,h,i)-pyrene and Indeno(1,2,3-cd)-pyrene. • Other pollutants such as: heavy metals (mercury, cadmium), alkylphenols (nonylphenol and octylphenol), PAH (Benzo(a)pyrene, fluoranthene, Benzo(b)fluoranthene and Benzo(k)fluoranthene), DEHP and diuron are also causing the downgrading of coastal water bodies. • For surface waters, combining all water categories, the most downgrading parameter is the sum of PAH Benzo(g,h,i)-pyrene and Indeno(1,2,3-cd)-pyrene (ubiquitous substances from combustion processes). They cause the non-achievement of good chemical status for 80% of the 1,814 surface water bodies in poor chemical status.

Chemical status of coastal water bodies in 2015

Chemical status of transitional water bodies in 2015

Authors: Statistical Observation and Data Service (SDES), French Biodiversity Agency (AFB).