THE DISTRIBUTION OF PADINA PAVONICA 53 



Between Cadiz and Torregorda: Seoane-Camba (1965), stn 86, ix, pools. 



Torregorda: Seoane-Camba (1965), stn 90, x.1959, rocks to the east, in protected pools. 



Conil: Seoane-Camba (1965), stns 109/110/111, iv.1959, north of Conil. 



Cabo Trafalgar: Seoane-Camba (1965), stns 128/130/131, near the Cabo, v.1959. 



Playa de la Victoria: Seoane-Camba (1965), vii.1960. 



Barbate: Seoane-Camba (1965), drift on shore, vi and viii. 



Tarifa: Clemente (1807); Seoane-Camba (1965), stns 178 (near Tarifa) and 181 (south of 

 Tarifa), iii to ix, always in somewhat protected sandy locations. 



Punto Camera: Seoane-Camba (1965), xii.1959. 



Algeciras: Clemente (1807); Seoane-Camba (1965), stns 193 (north of Algeciras), 203, and 

 204. 



General circumstances ofPadina in southern Spain obviously represent a transition from the 

 Atlantic coast into the Mediterranean, but it is convenient here to terminate detailed consideration 

 of data at the eastern boundary of Cadiz. The relationship between characteristics of Atlantic and 

 those of Mediterranean populations is discussed elsewhere. Only records from Huelva and Cadiz 

 are considered here; functionally, that means Cadiz alone, since no information has been traced 

 for the northern part of the Golfo de Cadiz. The reason for this may be the sandy and swampy 

 nature of that coastline, in large part known as 'Arenas Gordas' ( = coarse sands). The area is 

 strongly affected by outfall from various large freshwater systems, including the Guadiana River 

 (the Spain-Portugal coastal boundary); the Canales (Channels) that outfall near Huelva; and the 

 Guadalquivir. A coastline like this, largely lacking rocky substrata, is rarely attractive to phy- 

 cologists. Cadiz, by contrast, has considerable information, some as early as 1803. The most 

 detailed data derive from Seoane-Camba's (1965) study of the Cadiz littoral; he examined many 

 stations over the whole area from Sanlucar de Barrameda (the Guadalquivir mouth) in the north, 

 round to Algeciras in the east. Padina was present wherever habitat conditions permitted. Popu- 

 lations are possibly also present here in the shallow infralittoral ; Seoane-Camba's data represented 

 primarily intertidal and infralittoral fringe collections. Habitat demanded resembled that in 

 areas further north; that is, pools and wet conditions, on rocks covered by sand or detritus, 

 principally around low water and with some protection from direct wave-action. Some populations 

 were of considerable longevity; as with the distribution foci in England, the immediate area had 

 clearly borne Padina for many years, even though precise identification of consistent individual 

 populations was not possible. Specimens identifiable with Clemente and with Mertens, from Cadiz 

 or nearby, date from 1803, and Seoane-Camba recorded the alga from there in the years to 1965; 

 the 1803 specimens undoubtedly formed the basis for Clemente's (1807) published record from 

 Cadiz. He also recorded plants from Tarifa and Algeciras, both of which still carried populations 

 in 1959-60. 



The available data again provide some support for further breakdown of the seasonal periodi- 

 city generally found further north. Seoane-Camba (1965) recorded the alga from some stations in 

 March and April, and Clemente's (1803) Cadiz material appears to have been collected in April. 

 At Punto Carnero, Seoane-Camba noted Padina in December (1959), demonstrating further 

 merging into the situation outlined (Feldmann, 1937, and others) for the western Mediterranean, 

 where Padina is detectable as upright fronds over virtually the whole year. Surprisingly, Seoane- 

 Camba makes no mention for Cadiz of the association characterized by Padina and Cladostephus 

 that he recorded widely for the Ria de Vigo, northern Spain ; a very similar association had earlier 

 been recorded by Feldmann (1937), among others, from Cote des Alberes, on the Mediterranean 

 Spanish-French border. 



Discussion 



Trends in distribution 



This critical assessment of all traced data demonstrates so far as is possible the past and current 

 trends in distribution of Padina pavonica in the area covered. Many of the available signs indicate 

 the occurrence in comparatively recent times of quite profound changes toward the periphery of 



