Scottomyzon Gibberum (Copepoda) Associated With White Sea Starfish Asterias Rubens in Spatial and Temporal Aspects - Page 02

Some changes can be pointed out according to the population indexes in 2013. The population indexes decreased to almost zero in at Chernaya Rechka point. The depth at which starfish are collected was changed. In 2012 the depth of collection was 3 meters. In 2013 the starfishes were at a depth of 0.5 meters, and at a depth of 3 meters only juveniles were observed. The Chernaya Rechka point is characterized with salinity stratification because it belongs to the estuarine system. The reason for the significant reduction in the number of copepods can be the low salinity at the depth of 0.5 meters. The population indexes for other points remain at the same level as in 2012 year.

Points near the Babye Sea and the Polovye Islands are charaсterised with the highest levels of human impact and the highest population index value. The Polovye Islands are the closest to Poyakonda village where the level of human impact have increased through economic activities and the use of small boats. The Babye Sea has been characterized with the high intensity of the bottom sediment accumulation, which include various substances including pollutants, due to the hydrologycal and topographical features of a coastline.

Points near the Eremeevskye and Krestovye Islands are charaсterised with the lowest population index values. Laminaria saccharina dominate at these points (Poromov, 2014).

Symbioses can be used for the indication of the status of marine environment. The assessment of number of of symbionts can provide reliable information about the quality of the environment and more exact information about differences between ecosystem types. Symbionts are more sensitive to changes in the environment. Intensity and prevalence of the population of host by simbionts depends on complex conditions.

 

Conclusions

  1. The population indexes of starfish A. rubens by copepods S. gibberum increase during the growing season from June to September.
  2. The population indexes of starfish A. rubens by copepods S. gibberum increase with the depth and average size of starfish
  3. The population indexes of starfish A. rubens by copepods S. gibberum characteristic points depends on ecosystem type and human impact and can be used as environmental indicators.