Biological Sciences
Introduced algae
A newly introduced, large 'kelp' seaweed is threatening to become a major fouling problem in marinas and on boat hulls around the UK. The seaweed (opposite) grows up to 2.5 meters long and attaches to the sides of pontoons and boat hulls. Originally from Asia, the seaweed is thought to have been introduced to this country via boat hulls, from Brittany, where it is grown commercially for its food value. On the South Coast of England, it is established mainly in marinas so far. However, in these marinas it grows profusely on the sides of pontoon floats and on boat hulls.
Fieldwork and laboratory experiments carried out as part of a wider investigation into the ecology of Undaria in the UK. The experimental work described here was carried out in order to determine the growth, seasonality, and life history of Undaria in the UK. The above research includes studies on the gametophyte generation, carried out to investigate the growth and salinity tolerance of Undaria gametophytes, and to compare them with native species with which it will compete, such as Laminaria digitata.
Mature Undaria sporophyte from the Hamble UK.
Tethered Undaria sporophyte from growth experiments.
Mean lengths of all tagged Undaria plants at Port Hamble Marina, with SE
L. digitata gametophytes after 19 days in culture
Gametophytes are the microscopic generation of kelps which have a two-stage life cycle, the macroscopic generation are the sporophytes.
Research: An ecological and growth study of a non-indigenous population of Solieriaceaen algae.
by Sloyan Stray
Master student (Self-funded)
The research is based around a non-indigenous population of Solieria chordalis which is growing in Southsea Marina. The alga has formed a loose lying drift community upon the soft sediment of the marina base and is reproducing vegetatively. As is the case with many unattached algal populations this has led to a considerable degree of plasticity in the phenotype. The alga is non-indigenous to this area and consequently the morphology of the alga changes, both due to a drifting existence and to the different environmental variables placed on it by existing outside its native conditions. The alga is very abundant in the marina, forming large beds and is the main component of the mixed algae population.
The occurrence of such a population is of particular interest as there are similar reports of unattached plants of Solieria filliformis (Kützing) Gabrielson and Gracilaria verrucosa (Hudson) Papenf from comparable polluted environments on the south coast of Italy and Texas. The unusual quantity of algae found within the marina and its attributes as an excellent source of iota-carrageenan, nutrient stripper and high oxygen evolution has prompted investigation.
An ecological survey of the algal community contained within the marina aims to provide information of the local abundance, seasonal distribution, growth rate and any associated biota with this alga. As the alga is capable of withstanding polluted eutrophic environments, considerable self shading and has the ability to nutrient strip and evolve large amounts of oxygen its potential for mariculture is high. Red algae species, which produce high grade carrageenan, are in demand to supplement the harvesting of wild populations in order to meet the global demand for the alga and its phycocolloids. Potentially this species has the ability to be cultured in polluted waters and to improve the quality of its environment while giving a viable crop.
Laboratory growth experiments, using apical sections of the plant, will investigate the response of the alga to variations in salinity, temperature, irradiance and varying nutrient concentrations in order to establish optimal growth conditions. This study is laboratory based due to field growth studies being complicated by fouling algal species. The viability of the optimal conditions being attainable will be used to asses the potential for large scale mariculture of this species.