Wrack zone

Abstract: As part of a clarification of the response mechanisms of beach ground arthropods to the 2011 Tohoku-oki tsunami, a pit-fall trap survey was conducted in August and September 2012 and 2013 on four relatively flat sandy beaches in northern Tohoku region (i.e., northern Iwate to southern Aomori Prefecture) in Japan. At each beach surveyed, eight clean plastic cups with no baits were put for two days on each of the five beach zones (i.e., wrack, non-vegetated, short-herbaceous, tall-grass, and shrub zones). Among the ground arthropods in this study, we report the differences in susceptibility of two sandhoppers ( Trinorchestia trinitatisand T. longiramus), which dominate on the beaches and play an important role as prey for beach predators, to the tsunami, through monitoring their population dynamics. Although the abundance of the two species increased with time after the disturbance, T. trinitatishad a higher population growth rate than T. longiramus. In 2012, these two talitrid amphipods were collected mostly in the wrack zone, where the seaweed and driftwood accumulated, and on the non-vegetated zone near the shoreline, whereas they occurred in all beach zones in 2013. Since T. trinitatisburrows near the beach surface during its reproductive period in spring, this species might have suffered a large impact from the tsunami’s coastal erosion. On the other hand, our findings suggest that Trinorchestiaspecies rapidly recolonize coastal regions in a short period of time (within a year), due to their reproductive ability and the accumulation of sea wrack, which provides food and habitat to these sandhoppers.

Abstract: GROSS, M. F. V. KLEMAS, ANDJ. E. LEVASSEUR (Coll. Marine Studies, Univ. Delaware, Newark, DE 19716; Lab. de Botanique, Univ. de Rennes I, 35042 Rennes Cedex, France). Bull. Torrey Bot. Club 1 13:125-130. 1986.-A Spartina alterniflora Loisel. (Gramineae)-dominated salt marsh located along the Elorn River at ;48.5?N latitude near Brest, France, was studied to determine the distribution and zonation of the various plant species and to evaluate the biomass and other characteristics of S. alterniflora growing near the northern limit of its range in its non-native Europe. A general salt marsh community occupies the high marsh. Halimione portulacoides Aellen (Chenopodiaceae) lines the tidal creekbanks, but not the Elorn River banks. The remainder of the marsh is dominated by three distinct zones of S. alterniflora descending in elevation from the high marsh: middle marsh, wrack zone, and riverbank. The mean mid-August live aerial biomass (?1 s.e.) of riverbank, wrack zone and middle marsh S. alterniflora was 1181 ? 86 gdw/m2, 832 ? 90 gdw/m2, and 992 ? 48 gdw/m2, respectively. The height of the riverbank plants, the stem density in the middle marsh, and the dead biomass in the wrack zone were all significantly greater than the corresponding values for the other two zones. The presence of one stand of S. alterniflora which flowered in early July, a month earlier than the other plants, suggests that there were multiple North American latitudinal origins of the S. alterniflora growing in this marsh.

Abstract: . Mass aggregations of brown algae Cystoseira and seagrass Zostera (eelgrass), which are formed along the wrack line during storms and natural exfoliation, can be considered one of the underexploited primary resources of the Azov and Black Sea Fishery Basin. As a rule, the process of their aggregation falls on the summer - autumn season, which coincides with the high season, leading to people's discomfort during their recreation time. Therefore, the issue of the prospective utilization of algae storm debris, its harvesting and primary processing can be deemed quite vital. The investigated macrophytes, washed ashore during storms or seasonally, are the source of valuable materials; Zostera provides zosterin and fiber, and Cystoseira is rich in alginic acid, iodine and selenium. This article considers proven methods of algae processing for nutritional purposes, obtaining dietary supplements and cosmetic products, in paper manufacturing, and the use of macrophytes as fertilizers and animal fodder. The methods of primary processing, entailing the best possible preservation of quality of the investigated algae and involving the processes of drying, freezing and chemical treatment, are studied. Specifics of algae storm debris collection and the necessity of timely removal of macrophytes from sandy coastline are indicated. Recommendations on natural and artificial drying, freezing and salting of macrophytes are given.