Local knowledge about dugout canoes reveals connections between forests and fisheries

Dugout canoes are traditional boat types made from a single tree trunk. This type of boat can reveal unique connections between forest and fisheries in coastal areas: their construction and the species used depend on the local ecological knowledge of artisans and the plant resources available and are also influenced by the type of fisheries in which the canoe will be used. Our objective was to analyze how dugout canoes are constructed, maintained, and currently used in the central coastal region of Santa Catarina, Brazil. The study emphasizes the interaction between the use of forest resources and artisanal fishing in this coastal environment. The data collected were based on interviews with 30 artisans and participant observation. Schizolobium parahyba (Vell.) Blake, Ocotea porosa (Nees & Mart.) Barroso, Ocotea Aubl../Nectandra Roll. Ex Rottb., and Aspidosperma Mart. & Zucc. are the main taxa used to construct the canoes. Many canoe sizes are used, and based on the boat type, the trunk diameters needed to construct them varies from 0.6 to 2.9 m and trunk heights from 4 to 10 m. Different types of canoe are used according to the type of fishing and especially to the environment conditions. The construction of canoes in the region has decreased due to difficulties in acquiring wood, changes in fishing activities, and reasons related to labor and apprenticeship, all causes related to modernization of the society and urban growth. The knowledge of plant species used can contribute to shape policies to improve forest management. The survival of cultural practices in artisanal fishing communities should be stimulated in sustainable development programs, and it involves maintaining ecological and technical knowledge related to fishing and the plant resources used to manufacture and maintain fishing equipment.     

Artisanal fisheries of the Itaparica reservoir,São Francisco River,Brazil: socioeconomic profile,environmental dynamics,and management recommendations

Currently, artisanal fisheries in fresh water reservoirs have been losing ground to commercial fish farming and a great deal of fishery resources are being threatened by human interventions, such as reservoir management and increasing net-cage aquaculture. This study aims to understand the impacts of environmental changes on fishery resources and analyse the migratory fish breeding season as a missing link for fishery management in the semi-arid area of the São Francisco River Basin. Among the 870 fishermen operating in the Pernambuco part of the Itaparica Reservoir, 10% were interviewed and affirmed that fish stocks have been compromised due to the closed fishing period’s incoherence, exotic species insertion, and changes to the river flow caused by reservoir construction and operation. A significant correlation was observed between the Reproductive Activity Index (RAI) and precipitation (p?=?0.745) as well as between the RAI and the river’s flow (p?=??0.909). This shows how important it is to consider both the semi-arid climate setting and reservoir operation in determining the closed period which should safeguard fish reproduction. Monitoring the fish reproduction period and research on the reproductive biology of native fish species is needed in the São Francisco River Basin’s different stretches in order to guarantee valuable fish stocks and fisheries maintenance. Integrated action between the fish resource users, civil society, and federal bodies/agencies is essential in order to mitigate impacts and improve fish production systems, not only in Brazil, but in other regions experiencing a similar scenario.     

Environmental influence on commercial fishery landings of small pelagic fish in Portugal

Small pelagic fishes are particularly abundant in areas with high environmental variability (zones of coastal upwelling and areas of tidal mixing and river discharge), and because of this, their abundance suffers large inter-annual and inter-decadal fluctuations. In Portugal, the most important species in terms of landings are European sardine, Atlantic horse mackerel and Atlantic chub mackerel. Small pelagic fish landings account for 62.8 % of the total fish biomass and represent 32.7 % of the economical value of all catches. We have investigated trends in landings of these small pelagic fishes and detected the effects of environmental factors in this fishery. In order to explain the variability of landings of small pelagic fishes, we have used official landings (1965–2012) for trawling and purse seine fisheries and applied generalized linear models, using the North Atlantic Oscillation index (NAO) (annual and winter NAO index), sea surface temperature (SST), wind data (strength and North–South and East–West wind components) and rainfall, as explanatory variables. Regression analysis was used to describe the relationship between landings and SST. The models explained between 50.16 and 51.07 % of the variability of the LPUE, with the most important factors being winter NAO index, SST and wind strength. The LPUE of European sardine and Atlantic horse mackerel was negatively correlated with SST, and LPUE of Atlantic chub mackerel was positively correlated with SST. The use of landings of three important species of small pelagic fishes allowed the detection of variations in landings associated with changes in sea water temperature and NAO index.     

Climate-induced changes in fish landings of different fleet components of Portuguese fisheries

For each Portuguese fleet component, landings of biogeographic groups of fish species were compared for the period of 1993–2009. Wide-distribution species were the most abundant in landings, but have shown a decreasing trend. Temperate species had higher landings in trawl fisheries, whereas subtropical species were most abundant and exhibiting an increasing trend in landings of multi-gear fisheries. A latitudinal gradient was observed, with landings of temperate species being more important in the North-western coast than in the South-western and South coasts. Although trawl fisheries were relatively more important in the North-western coast, there has been a recent increase in the relative importance of multi-gear fisheries and of subtropical species in this area. The increasing relative importance of subtropical species in Portuguese fisheries along with the fact that landings of subtropical species were higher in multi-gear fisheries could indicate an easier adaptation of Portuguese multi-gear fisheries to the effects of climate change. However, as multi-gear fisheries include a wide range of gears, techniques and target-species, they may not all respond in the same manner to changes in fish species’ distribution. Among multi-gear fisheries, trammel nets catch a wider variety of species and a wider size range than gill nets or longlines; thus, trammel net fishers can adapt to changes in abundance of the main target species more readily than those using more species- and size-specific gears. Therefore, trammel net fisheries could more easily adapt to the effects of climate change on fish distribution than gill net or longline fisheries.     

Biological responses to nine powerful typhoons in the East China Sea

Using multi-satellite remote sensing and numerical model data, we investigated the biological responses to nine powerful typhoons that affected the East China Sea (ECS) between 2010 and 2013. The spatial distribution patterns of the surface chlorophyll-a (Chl-a) in response to the passage of typhoons were quite different. Some typhoons clearly induced phytoplankton blooms in part of the surface seawater, whereas the Chl-a concentrations were not significantly altered by the other typhoons. In the case that the ocean’s precondition was similar, the pre-typhoon Chl-a concentration and transit time were the main factors that affected the post-typhoon Chl-a concentration. Besides strong vertical mixing and upwelling, the surface current change and heavy precipitation induced by the typhoons also influenced the distribution and growth of phytoplankton in surface seawater after passage of individual typhoons. In addition, the typhoons that directly affected coastal regions increased the nutrient concentrations in these areas, which influenced the occurrence of red tides in the ECS over a long time scale.     

Resilience thinking applied to fisheries management: perspectives for the mullet fishery in Southern-Southeastern Brazil

The mullet fishery system encompasses a complex arrange of ecological and socioeconomic factors interacting in multiple scales on the Southern-Southeastern Brazilian coast. Similarly, to other fisheries in developing countries, overfishing and poor governance have been threatening the resilience of the mullet fishery. In this paper, we explore aspects related to fisheries management from the perspective of the concept of resilience. The industrial and artisanal fishery sectors represent the different stakeholders. The main issues of concern are related to failures in the fisheries management to properly address equity in resource access and resource use sustainability among stakeholders. Asymmetry in technology and political and economic power affect food security and income generation especially for subsistence and small-scale fishing. Despite changes in rules-in-use, overfishing and conflicts between resource users are still relevant. Fishery dynamics and resource availability are greatly affected locally by forces such as pollution, urbanization, non-selective fishing, and regionally, by the El Niño Southern Oscillation (ENSO), and industrial (purse-seine) fishery. Considering the influence of ENSO on this fishery, a time span of at least 7 years to investigate this system could provide better answers to improve the management. Effective resilient fisheries should rely on three aspects. First, there should be a flexible fish allocation system based on ecosystem variability. Secondly, fish allocation should prioritize food security and poverty alleviation. Thirdly, a monitoring system should be implemented that takes into consideration ecosystem, fisheries and human dimensions to support a flexible and adaptive fisheries management, with resilient fisheries as an ultimate goal.     

Implications of future bioclimatic shifts on Portuguese forests

As climate is an important driver of vegetation distribution, climate change represents an important challenge to forestry. We (1) identify prevailing bioclimatic conditions for 49 relevant forest species in Portugal and (2) assess future shifts under climate change scenarios. We compute two bioclimatic indices (aridity and thermicity) and a new composite index, at ~1 km spatial resolution, and overlap with the species’ current ranges. Locations are based on a digital inventory, while climate parameters for both recent-past (1950–2000) and future climates (2041–2060), under RCP4.5 and RCP8.5, are provided by a multi-model ensemble of climate simulations. Results for future scenarios highlight an overall warming and drying trend. Supramediterranean and mesomediterranean climates will be significantly reduced, while thermomediterranean climates will dramatically increase, from their almost absence in current conditions to an area coverage of ~54 % in 2041–2060 for RCP8.5. There is also a clear shift from hyper-humid and humid to sub-humid and from the latter to semi-arid climates (area coverage of ~13 % in 2041–2060 for RCP8.5). Lower thermomediterranean sub-humid to semi-arid zones will cover the southern half of Portugal. These projections identify the most vulnerable (e.g. Betula pubescens, Quercus pyrenaica and Castanea sativa) and the most adapted (e.g. Quercus suber, Q. rotundifolia, Ceratonia siliqua, Pinus pinea, Quercus coccifera) species in future climates. Current bioclimatic zones associated with Eucalyptus globulus and Pinus pinaster, economically relevant species, will be moderately reduced and relocated. Possible adaptation measures are discussed to improve forest resilience to climate change, while maintaining its economic and environmental benefits.     

Species richness,structure, and conservation of <Emphasis Type="Italic">Nitraria retusa</Emphasis> communities in the coastal salt marshes of Kuwait

Although the coastal salt marshes of Arabian Gulf have been altered extensively by human development activities, there is a paucity of data describing changes in the distribution and abundance of native coastal plant communities. The main objectives of this study are to determine vegetation condition, size structure, and conservation status of Nitraria retusa, a medicinal and salt-tolerant shrub, in disturbed and non-disturbed coastal salt marshes of Kuwait. Size measurements of Nitraria shrubs and nabkas, which are mounds of sediment developed around shrubs, were carried out in 50 quadrats (20 × 20 m²), randomly selected inside and outside Sabah Al-Ahmad Natural Reserve. Species richness and soil properties of nabkas and interspaces, the open areas between the nabkas, were also measured. The results revealed that nabkas of Nitraria in non-disturbed sites are more stable and rich in plant diversity than those in disturbed sites. Mean height and mean canopy diameter of Nitraria shrubs, total plant cover, and species richness are significantly higher in non-disturbed sites than disturbed sites, which indicate the positive influences of conservation for long term on vegetation structure and species richness. The results of soil analyses indicate the important role of nabkas in providing refuges for plant life and species diversity. The present study indicates that more than 50 % of the N. retusa community has been lost during the last few decades. Therefore, N. retusa should be considered an endangered species in Kuwait. The reduction in vegetation cover, a decline in species richness, and the overall degradation of salt marshes are attributed to human development activities along the coast of Kuwait. Effective conservation actions for threatened species in degraded coastal salt marshes of this region include establishment of protective enclosures, prohibitions on development that adversely affects native plant communities, and the planting native salt-tolerant shrubs to facilitate regeneration.     

Regional challenges in tourist wetland systems: an integrated approach to the Ria Formosa in the Algarve, Portugal

Coastal change and coastal erosion have been a long-existing source of environmental changes. Traditionally, regional changes in wetland systems and their relations to agriculture, industry and urbanization are a major cause for concern. Nowadays, coastal distress has reached even global proportions: the problems of coastal change are strongly linked to the loss of fragile ecosystems, eutrophication and loss of biodiversity. Given that over 70 % of all human activity is in coastal areas, it is clear that many environmental and socio-economic changes occur at a local level and manifest themselves in a spatial context. The physical effect on the geographic morphology is evident in the related consequences for land use. A deep understanding of the changes in land use, and simultaneously in coastal erosion, calls for the integrated monitoring of the most relevant effects in fragile regions. The Ria Formosa wetland system is a unique and very special wetland system in the Algarve (Portugal) and has been integrated in the NATURA 2000 network. The strong symbiosis between nature, agriculture and fisheries, as well as tourism, in the Algarve has led to spatial-ecological synergy. By using coastal recession analysis techniques by means of remote-sensed imagery from 1987, 1989, 2000 and 2007 and by combining this information with available data sets on surface erodibility, a cost surface on multitemporal transitions of land-use classes from the CORINE Land Cover data allows us to assess and integrate a decision-making framework by means of GIS. The novelty of this combined approach to land-use management is the blend of spatial analysis and remote-sensing techniques that share important information on ecosystems at risk. Our findings suggest a growing concern to the area brought by anthropogenic activity. This is studied to a spatial accounting of the distribution of land changes and transitions, where (1) a significant loss of coastal area is witnessed along the Ria Formosa, leading in particular to loss of agricultural land. (2) This loss is underpinned by an increase in leisure facilities to respond to the tourism demand of the region of the Algarve, while landscape metrics suggest that these areas are more volatile for coastal erosion. (3) Simulation through Markov chains on the land use and effects of urban, agricultural, forest and wetland dynamics suggests that by 2026, it is expected to continue to have an increase in urban land, leading to an augmented vulnerability of coastal erosion processes brought by the loss of forest areas which protect from erosion given the root system that directly protects from the existing wave energy and helps sedimentation processes. The above methodology and the availability of data that are freely available render such a combined approach interesting for many other regions of the world, where tourism, coastal change and regional balance are of the utmost importance for sustainable development. The advanced research tools presented here are of critical importance for coastal zone degradation management.     

Direct and indirect effects of climate and fishing on changes in coastal ecosystem services: a historical perspective from the North Sea

Humanity depends on the marine environment for a range of vital ecosystem services, at global (e.g. climate regulation), regional (e.g. commercial fisheries) and local scales (e.g. coastal defence and recreation). At the same time, marine ecosystems have been exploited for centuries, and many systems today are under stress from multiple sources. Recent studies have shown how both climate change and fishing have caused long-term changes in the marine environment. However, there is still poor understanding of how these changes influence change in coastal ecosystem services. In this paper, an integrated modelling approach is used to assess how the final delivery of marine ecosystem services to coastal communities is influenced by the direct and indirect effects of changes in ecosystem processes brought about by climate and human impacts, using fisheries of the North Sea region as a case study. Partial least squares path analysis is used to explore the relationships between drivers of change, marine ecosystem processes and services (landings). A simple conceptual model with four variables—climate, fishing effort, ecosystem process and ecosystem services—is applied to the English North Sea using historic ecological, climatic and fisheries time series spanning 1924–2010 to identify the multiple pathways that might exist. As expected, direct and indirect links between fishing effort, ecosystem processes and service provision were significant. However, links between climate and ecosystem processes were weak. This paper highlights how path analysis can be used for analysing long-term temporal links between ecosystem processes and services following a simplified pathway.     

Trends in environmental education for biodiversity conservation in Costa Rica

Costa Rica is internationally recognized for its abundant biodiversity and being a leader in the promotion of education strategies for biodiversity conservation. We interviewed staff from 16 institutions developing key environmental communication, education, and participation projects for biodiversity conservation in the country. Through content analysis, hierarchical cluster analysis and Chi-square tests, we examined the characteristics of the projects carried out by these institutions and developed a typology of four categories derived from six variables: primary audience, content, project purpose, location, scale, and facility. Then, we designed a conceptual model describing the integration of conservation and economic development in the educational projects. We found two key approaches related to this integration: vision of nature protection which aims to inform audiences of ecological concepts and focuses on schoolchildren and vision of sustainability which engages adult audiences and is management-oriented. Education for community-based environmental management may serve as a good example of educational projects which integrate conservation and economic development, implementing a vision of sustainability.     

Mitigation of illegal fishing activities: enhancing compliance with fisheries regulation in Lake Victoria (Kenya)

Overexploitation of living resources severely affects aquatic ecosystems and is among the most serious environmental issues worldwide. Lake Victoria, the second largest fresh water lake in the world, provides food and jobs to almost 30 million people in three African countries and is nowadays facing significant decrease in fish stock due to its unsustainable use. To analyse reasons behind the illegal fishing activities in the Kenyan part of the lake, the survey programme was designed based on a rational choice framework, and data analysis on compliance with fisheries regulatory law was carried out. Selection of explanatory variables to be considered was guided by the “Table of 11”, which is a tool elaborated for the Netherlands’ Ministry of Justice to analyse the regulated community’s behaviour and motivations. Key findings of the study show that existing economic environment and weak enforcement contribute to the low compliance with the fisheries regulations and lead to further degradation of the lake ecosystem.     

Fishers’ perceptions of climate change,impacts on their livelihoods and adaptation strategies in environmental change hotspots: a case of Lake Wamala,Uganda

Fisheries resources support livelihoods of fishing communities but are threatened by over-exploitation, habitat degradation, pollution, invasive species and climate change. Unlike the other threats, climate change has received limited consideration and reducing its risks requires appropriate adaptation strategies. This study used quantitative and qualitative methods to generate knowledge on fishers’ perceptions of climate change, changes in climate variables and their impacts on livelihoods, adaptation strategies, constraints to adaptation and required interventions to promote adaptation strategies that would enable fishers to build resilience to sustain their livelihoods. We found that fishers were aware of changes in climate conditions manifested by unpredictable seasons, floods and droughts. Fishing remained the main livelihood activity. However, the dominance of fishes had changed from Nile tilapia (Oreochromis niloticus L.) to the African catfish (Clarias gariepinus Burchell). Floods and droughts were associated with damage to gears, boats, landing sites and changes in fish catches and sizes, income from fishing and fish consumption. The fishers adapted by increasing time on fishing grounds and changing target species and fishing gear among other things. Some innovative fishers diversified to high-value crops and livestock. This increased their income beyond what was solely earned from fishing which provided an incentive for some of them to quit fishing. Livelihood diversification was enhanced by use of communications technology, membership of social groups, increasing fishing days and fishing experience. Adaptation was, however, constrained by limited credit, awareness and access to land, which require interventions such as improving access to credit, irrigation facilities, appropriate planting materials and awareness raising. We identified adaptation strategies, which if promoted and their constraints addressed, could increase resilience of fishers to the influence of climate change and sustain their livelihoods.     

Beyond fishermen’s tales: contributions of fishers’ local ecological knowledge to fish ecology and fisheries management

Studies investigating the local ecological knowledge (LEK) held by fishermen about the fishing resources have indicated that fishermen’s LEK may have the potential to improve fishery management, by providing new information about the ecology, behavior and abundance trends of fish and other aquatic animals. Our major aim is to undertake a brief review of published ethnoichthyological studies with a focus on coastal Brazilian fisheries and freshwater fisheries in both Brazil and Southeast Asia. Based on such review, we provide 29 hypotheses on fish ecology based on fishermen’s LEK and compare them with what is already known from the biological literature, using an arbitrary ‘likelihood’ measure: “Low likelihood” corresponded to unexpected hypotheses, which contradict existing biological data. “Medium likelihood” corresponded to hypotheses that could not be compared to available scientific knowledge. Hypotheses that agree with scientific data were considered as “High likelihood”. We therefore discuss these three categories of hypotheses about several distinct topics, such as migration, reproduction, feeding habits, abundance patterns, ecological relationships between fish and their predators, and fishing pressure. Our results may contribute to the fisheries management and research in the studied regions and other similar places, besides raising the interest of biologists to properly include fishermen’s LEK when planning and conducting fisheries surveys. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

Pleistocene Refugia for <Emphasis Type="Italic">Calluna vulgaris</Emphasis> (L.) Hull Populations in the European Atlantic Region

The distribution of nine chloroplast DNA haplotypes in four insular North-Atlantic and four European coastal Atlantic populations of Calluna vulgaris in the glacial zone of the range has been analyzed in comparison with that in six marginal southern populations in the nonglacial zone of the Atlantic and Mediterranean regions. As a result, two hypothetical Pleistocene refugia (HPRs) for this C. vulgaris population group have been revealed, one in the Cévennes mountain range and the other in the Southern Alps (Trento). Judging from the 1–F_ST value, it has been found that the group of populations in the glacial Atlantic zone and adjacent European coastal Atlantic region is genetically similar to the HPR in the Cévennes at a highly significant level (p ≥ 0.999) and less similar to the HPR in Trento; however, it differs significantly from other Mediterranean and Atlantic populations. It has been concluded that the most probable hypothetical Pleistocene refugium for the recent C. vulgaris populations of the northeastern Atlantic and European coastal Atlantic regions was in the west of the Mediterranean, in the Cévennes, while the additional refugium was in the Southern Alps. Possible directions of the postglacial dispersal and recolonization of habitats by C. vulgaris populations from the western Mediterranean to the northeast of the Atlantic and to Scandinavia have been revealed.     

Habitat suitability for the Caucasian frog <Emphasis Type="Italic">Rana macrocnemis</Emphasis> Boulenger, 1885 (Amphibia:Anura: Ranidae)

Modeling the distribution patterns of species is a generally efficient tool to assess their ecological characteristics. In this study, we compared ecological niche factor analysis (ENFA) and maximum entropy (Maxent) techniques to predict the most suitable distribution range of Rana macrocnemis. The Maxent model predicted potential suitable habitats for R. macrocnemis with high success rates (AUC Training data = 0.877 ± 0.039). According to the map constructed, three important variables had high contribution to species presence: temperature (50.4%), land cover (24.6%) and elevation (14.4%) variables. The ENFA results were relatively similar to Maxent jackknife analysis. The results implied that R. macrocnemis prefers grassland and needle leaf deciduous forest with high elevations, and low temperature.     

Trends in landings of fish species potentially affected by climate change in Portuguese fisheries

Fisheries are an important source of food, with a high economic value and social significance. The present worrying situation of the world fisheries is the result of the interaction between different factors (e.g. climatic variations, natural oscillations, technological innovation), but the greatest challenges are overfishing and climate change. The species richness of the Portuguese coast is generally higher than that found in northern Europe and similar to that of the Mediterranean, since many species have their southern or northern distribution limits along the Portuguese coast. The zoogeographic importance of this latitudinal area has long been recognized, representing the transition between north-eastern Atlantic warm-temperate and cold-temperate regions, which makes the Portuguese coast an area of great sensitivity to the detection of climate change. Official landing data for commercial species that have the Portuguese coast as their distribution limit were analysed together with sea surface temperature for the period of 1927–2011. In general, landings of species with affinity for temperate waters presented a decreasing trend, whereas species with affinity for subtropical/tropical waters showed an increasing trend. These variations were associated with variation in temperature: lower landings of temperate species occurred mainly in warm years, whereas landings of subtropical/tropical species presented an opposite trend, with higher landings in warm years. Preparing for the impacts of climate change is crucial for the sustainability of fisheries. Management should take into consideration information about environmental factors that affect species distribution and abundance.     

Most Interesting Findings from Remnants of Chironomid (Insecta: Diptera: Chironomidae) Larvae in Layers of a 200-Year-Old Stratum of Lake Oron Bottom Sediments

The remnants of chironomid larvae from layers of the 10-cm-thick bottom sediment in Lake Oron have been studied. Six taxons unknown in the current chironomid fauna of the lake have been identified: Abiskomyia rivalis, Corynoneura arctica-type, Mesocricotopus thienemanni, Metriocnemus eurynotus-type, Nanocladius rectinervis-type, and Robackia pilicauda. The most probable reasons for the disappearance of these species from the Oron fauna, which are related to environmental changes caused by global climate changes, are considered.     

Variation in the Composition of Secondary Metabolites in <Emphasis Type="Italic">Flavocetraria</Emphasis> Lichens from Western Siberia

The composition and contents of secondary metabolites in Flavocetraria lichens from Eastern Siberia were analyzed using herbarium specimens. Based on the composition of identified metabolites, three F. cucullata chemotypes and two F. nivalis chemotypes were distinguished. Distinct geographic differentiation between the F. cucullata chemotypes was revealed, probably reflecting their adaptation to environmental conditions. The content of usnic acid in F. cucullata thalli was found to correlate with the latitude of growing region. This may be regarded as evidence for a protective role of this metabolite in lichens growing at high latitudes and exposed to excess solar irradiation during the polar day.     

An assessment of two decades of trace metals monitoring in wild mussels from the Northwest Atlantic and Cantabrian coastal areas of Spain, 1991–2011

Since 1991, the Instituto Español de Oceanografía has monitored the concentrations of trace metals in wild mussels from the north (Cantabrian Sea) and northwest (Atlantic) coasts of Spain to define geographical distributions and temporal trends. While Cu, Zn and As concentrations presented fairly uniform geographical distributions, Hg and Pb concentrations were higher in mussels from the Cantabrian sea region as a result of historical anthropogenic activities. Cd, on the other hand, appeared to be more affected by natural processes on the northwest Atlantic coast (i.e., upwelling) than by human activity. Approximately 70% of the paired observations showed downward trends, 50% of these significant, with time. An improvement in environmental conditions along the northern coasts of Spain is evident despite that some metal levels resulted above the Background Assessment Concentrations given by OSPAR to assess potentially harmful occurrences.