North Coast Of Spain Research Articles

Seasonal nitrogen metabolism in an intertidal population ofGelidium latifolium(Gelidiaceae, Rhodophyta)

The nitrogen status of Gelidium latifolium on the north coast of Spain was monitored for a 2 year period from 1990 to 1991. Each summer, the population showed obvious symptoms of nitrogen (N) limitation, such as thallus ‘bleaching’. Minimum N content (as % of dry weight), highest C/N ratio (above 45) and lowest protein (< 10% dry weight) and phycobilin contents were observed during summer, when nitrate availability in seawater was lowest, and temperature and light levels were highest. However, tissue N content did not respond to a short local upwelling period that increased nitrate levels in seawater more than ten-fold. The effect of seawater N concentration and increased light levels on pigment content was established experimentally. N-starved plants placed in N-enriched seawater during summer 1990 showed increased levels of phycobilin and chlorophyll a compared with an unenriched control. Screens which transmitted different proportions of natural light placed over a Gelidium latifolium population during...

Diel variations in the vertical distribution of copepods off the north coast of Spain

Diel variations in the vertical distribution of copepods were studied in the north coast of Spain and related to the physical and biological structure of the water column. Zooplankton samples were taken at three different stations during a 24 h period, in the proximity of a drogue buoy using a Longhurst Hardy Plankton Recorder (LHPR) sampling net, so that it is assumed that the same water mass was sampled continuously. Physical and other biological parameters were monitored by Conductivity Temperature Depth Recorder (CTD) profiles and vertical Undulating Oceanographic Recorder (UNDULATOR) dips for temperature, salinity, and chlorophyll a. Copepods were counted and classified into seven categories according to their size, and their distribution in the vertical plane was analysed using univariate and multivariate statistical techniques.Vertical distribution of copepods and their developmental stages were mainly determined by chlorophyll distribution and, when a subsurface chlorophyll maximum was present, small copepods and copepodite stages appeared aggregated in this layer. Nocturnal upward movements of the population and an ontogenetic component in the position and behaviour of the community were also important features that characterised the distribution of the community. Those patterns may explain a part of the observed variability of the abundances and distribution of the copepods in the water column. However, the water mass displacement in the 24 h period of study must also be considered as a main variability factor in the spatial and temporal distribution of the zooplankton populations.

Modelling the coliforms inactivation rates in the Cantabrian sea (bay of Biscay) from in situ and laboratory determinations of T90

Precommissioning studies of proposed outfalls along the north coast of Spain included in situ and laboratory determinations of T90 values directed at the development of a local-specific inactivation model. The effect of salinity, light intensity, temperature and depredation on inactivation (T90) of Escherichia coli, was studied in unifactorial experiments carried out in the laboratory. The values of T90 obtained fitted the exponential model of die-off for the first three variables (salinity, light, temperature: R &amp;gt; 0.93). Light intensity showed the greatest bactericidal effect, with T90 values near or lower than 1 hour, when light radiation was greater than 120 Wm−2. The logarithm of T90 showed a linear relationship with each one of these three factors. Nevertheless, the global relationship which best fits the values obtained was not linear in its coefficients. The values of T90 estimated from experiments in situ, carried out in summer (33.6 min) and winter (116.8 min), reflected the seasonal differences in the environmental conditions in this zone, mainly from light intensity. Differences between these values and those obtained applying the model pointed out the need to study in depth the effect of light on the bacterial die-off in natural systems.

7-ethoxyresorufin O-deethylase (EROD) and antioxidant enzyme activities in larvae of sardine ( Sardina pilchardus) from the north coast of Spain

Sardine larvae ( Sardina pilchardus) and their major food source (mixed zooplankton) were sampled from four sites along a transect out of the Bilbao estuary and a fifth (reference) site further along the north coast of Spain (23.5.92-10.6.92). Whole body sardine larvae were assayed for 7-ethoxyresorufin O-deethylase (EROD) activity (measure of CYP1A) as a biomarker of exposure to organic pollution, and the antioxidant enzymes catalase (EC 1.11.1.6) and superoxide dismutase (SOD; EC 1.15.1.1) as potential biomarkers of oxidative stress. EROD activity was lowest at a site closest to the Bilbao estuary, and increased along the transect until it reached levels recorded from samples for a reference site. Both catalase and SOD activities were highest at the inshore site of the transect decreasing offshore before increasing again at the site furthest from the coastline. Levels of organic contaminants (polycyclic aromatic hydrocarbons (PAHs), polychlorobiphenyls and pp'DDE) in mixed zooplankton were generally similar at the different sites, with the exception of higher PAHs at the extremes of the transect and at the reference site. The results are discussed in relation to the biomarker application of fish larvae, CYP1A and antioxidant enzymes.

Conservation and restoration of endangered coastal areas: The case of small estuaries in Northern Spain

The extent of degraded estuarine and wetland zones on the north coast of Spain is discussed. A method for the analysis and diagnosis of such zones is proposed. The method is based on the identification and mapping of homogeneous environmental units and the definition of indicators for the assessment of these units in terms of attributes relevant for restoration and management. The specification of a set of criteria enables the diagnosis maps thus obtained to be transformed into maps with proposals for management actions, for which specific designs are proposed. The cost of the actions proposed is also estimated. The results obtained from the analysis in three small estuaries are extrapolated to determine the possible extent of different rehabilitation activities and to estimate the cost of recovery plans for the whole coastal sector analysed.

Environmental mapping applied to the planning of urban and natural park areas in the north coast of Spain : Frances, E; Diaz de Teran, J R; Cendrero, A; Gomez Orea, D; Villarino, T; Leonardo, J; Saiz, L Proc 6th International Congress International Association of Engineering Geology, Amsterdam, 6–10 August 1990V1, P95–101. Publ Rotterdam: A A Balkema, 1990

Environmental mapping applied to the planning of urban and natural park areas in the north coast of Spain : Frances, E; Diaz de Teran, J R; Cendrero, A; Gomez Orea, D; Villarino, T; Leonardo, J; Saiz, L Proc 6th International Congress International Association of Engineering Geology, Amsterdam, 6–10 August 1990V1, P95–101. Publ Rotterdam: A A Balkema, 1990

A poleward flow along the Atlantic coast of the Iberian peninsula

Satellite Advanced Very High Resolution Radiometer (AVHRR) imagery and Argos tracked drifters have revealed the existence of a narrow, warm surface poleward current along the Iberian coast during autumn and winter. Six near‐surface drifter tracks indicated a net northward flow between September 1986 and March 1987, although individual drifter trajectories also provided evidence of eddy activity and episodes of equatorward flow. A SeaSoar survey during September 1986 in the region 37°–43°N, 9°–11°W showed that poleward flow at that time was associated with the northward advance of a warm, salty tongue of water throughout the upper 400 m layer. Infra‐red imagery confirmed the northward penetration of the warm current and its progression around Cape Finisterre along the north coast of Spain during the course of the winter. A similar situation is indicated by satellite imagery during other years. Current meter data show that poleward flow occurred along the continental slope down to depths greater than 600 m. Conductivity, temperature, and depth (CTD) casts show the presence of Mediterranean Intermediate Water (MIW) at depths greater than 600 m. The MIW does not flow as a simple northward flowing jet along the continental slope off Iberia, but instead shows evidence of eddies within the flow. The poleward surface current is in the opposite sense to the general summer circulation of the region, when cool upwelled water is advected equatorward. It is postulated that the poleward flow is generated by thermohaline forcing when the southward trade winds, characteristic of the summer months, weaken or reverse. Intermittent poleward flow appears to be a common characteristic of the Eastern Boundary throughout the North Atlantic from West Africa to the Norwegian Sea.

Ecology of Sargassum muticum on the North Coast of Spain. Preliminary Observations

Ecology of Sargassum muticum on the North Coast of Spain. Preliminary Observations

A study of the impact of industrial fluoride emissions on a rural environment.

In this note we study current fluoride levels in the area of Onton, Cantabria (Spain), in the vicinity of a factory whose main industrial activity is the production of fluoride compounds. When the factory opened in the early 1970s, it was the source of a serious pollution problem; an increasing number of cases of fluorosis in cattle on farms near the factor were detected in addition to extensive damage to vegetation. Although the company implemented an antipollution plan to minimize fluoride emission levels in 1975, this problem has not yet been solved. The factory is situated by the sea on the north coast of Spain in a mountainous area. Two valleys stretch south and southeast of the factory in the direction of the prevailing winds. The climate is mild and wet. Since stock-raising is the dominant activity in the region, the area is mostly devoted to pasture. The study, which was done in 1986, measured fluoride concentrations in air, surface water, and pastures, and in milk and urine samples from cattle.

Long-Term Analysis of Wave Climate Using Short-Term Techniques

This paper proposes a number of theoretical probability distributions for variables of interest when planning operations at sea. Examples of such variables are: duration of storms, duration of calms, intensity of storm peaks, etc. The theoretical distributions are obtained by means of random process theory applied to the curve of evolution of Hs (significant wave height). The model is checked with six years of wave data recorded at the north coast of Spain.

ON A SEQUENTIAL BEHAVIOUR OF SEA-STATES

Probability distributions theoretically derived for gaussian, stationary processes are applied here to the sequential behaviour of sea-states. This behaviour defined by the curve of evolution of significant wave-height, Hs(t), is characterized by variables such as: intensity of storm peaks,time between beginnings of storms, average duration of calms and storms, average number of consecutive storms, expected value of the extremal storm peak, etc. The distributions obtained for these variables heve been tested with 5 years of wave data, recorded in the north coast of Spain. The agreement obtained is satisfactory in most cases, showing the validity of the approach and its applicability to situations in which only a limited amount of data is available. However, in cases where a large volume of data exists, empirically selected distributions could provide a marginally better fit.

Environmental geology of the santander bay area, northern Spain

The Santander Bay area on the north coast of Spain has been selected for a study comparing its environmental geology features with the resource capability, and present land and water use. The environmental geologic map of the Santander Bay area consists of 53 environmental units grouped into six major environmental systems.Systems are process-defined, whereasunits are defined according to active processes, landform, physical properties of the materials, biologic assemblages, and man's influence. In each case the feature considered to be of first-order environmental significance is used to define the unit, but all other features are included in its description. With the information available at present, only qualitative characterization of the units has been possible. Capability or carrying capacity of the environmental units has been evaluated and mapped in relation to 21 types of human activity, derived from different land-use practices. The evaluation is by a matrix. Capability of the units is a consequence of their properties, but no capability judgments are implied in the definition of the units. It is convenient to distinguish between activities which are harmful for the environment if carried out on a certain unit and activities for which certain units might be unsuitable or hazardous to man. Some of the present land-use practices are in conflict with the natural capability of the units. Particularly threatened is the bay-estuarine system, especially the marshes and intertidal areas. From the data presented, information pertinent to land-use planning can be obtained, especially about units which are adequate for waste disposal, units which should be preserved, and units suitable for construction. More precise, quantitative characterization of the environmental units should be undertaken immediately. This would make possible the formulation of land-use planning policies in accordance with the natural capability of the environment. Planning according to capability of the units will allow maximum use of the natural resources of the area with minimum environmental damage.

The surface swarming ofPolybius henslowi[Brachyura: Portunidae

A dense population ofPolybius henslowiLeach was recorded at the surface of the sea 15 miles off the north coast of Spain. The depth of water at this point was 1740 m. Visual observations of the swimming behaviour show thatPolybiustends to swim with the body facing diagonally and backwards against the current. The space between individuals appears to be maintained deliberately and was never less than 6 ft. during daylight. Measurements show that there are at least two sizegroups present. Females represent 40% of the total of 251 animals collected, and these were at approximately the same reproductive state with the ova maturing. The males are on average 2·3 mm longer than the females. No food was found in the stomach of any of the animals taken.

A Newly-Discovered Transition Culture in North Spain

The story of humanity during the period that elapsed between Palæolithic and Neolithic times has proved an intriguing problem to prehistorians for a long time. The Azilian culture (discovered by Piette in the cave of Mas d'Azil) resting as it does on the older Palæolithic industries and covered in turn by layers of Neolithic and Eneolithic age, seemed to bridge the gulf. But the Azilian culture has only a limited distribution and is truly Palæolithic, as is shown by the absence of the remains of domestic animals and pottery. Again, the Tardenoisean culture, with its pigmy industries and typically pigmy burin seemed to supply a bridge, and here we find a culture of wide extent. As before, however, we are still dealing with a Palæolithic culture, and its age in Western Europe (as has been shown at the diggings of Valle) is contemporaneous with the latter part of the Azilian. After the Azilio-Tardenoisian culture came the early Neolithic of which little can be told except in certain localised areas. Now another chapter of the story of these times, mainly referring to Asturias on the North coast of Spain (but including the area further East as far as Biarritz and also embracing sites in North Catalonia) has been added through the perspicacity of the Count de la Vega del Sella, who has unearthed a new and most interesting post-Azilio-Tardenoisean but pre-real Neolithic culture.

Geographical Notes

M. A. HAUTREUX has been engaged this summer (Bulletin of the Bordeaux Society of Commercial Geography, 1893, No. 14) in investigating the difficult question of the currents of the Bay of Biscay, by means of specially contrived floats consisting of two bottles attached by a cord a metre in length. The lower bottle being weighted with water keeps the upper one, containing air, from being driven by the wind, nnd the whole drifts along with the superficial layer of water. The results obtained seem to point to the absence of any current northward along the coast of the bay. From all points of the line at which floats were discharged west of France they showed a tendency to drift rapidly south-eastward towards the south-eastern angle of the bay. The observations will be continued, and the result will be of value in furnishing additional information to sailors of the landward drift that has so often proved fatal to vessels on the north coast of Spain.