Effects of waterfowl, large fish and periphyton on the spring growth of Potamogeton pectinatus L. in Lake Mogan, Turkey

Abstract

It has been argued that waterfowl and fish may threaten growth of submerged macrophytes, especially in spring during the early growth phase when plant biomass is low. A small reduction of biomass at that time might delay growth or decrease subsequent productivity. We investigated the impact of waterfowl and large fish on the spring growth of fennel pondweed (Potamogeton pectinatus L.) by employing an exclosure experiment in the macrophyte-dominated clear-water Lake Mogan, Turkey. Birds and large fish were excluded from eight plots and both in situ vegetation and macrophytes kept in pots were compared to eight open plots. Also, to investigate the effect of periphyton on plant growth it was removed from half of the pot plants. Exclusion of waterfowl and fish may decrease predation on macroinvertebrates, which in turn may affect periphyton, and macrophyte growth, why macroinvertebrates also were sampled. Waterfowl density was high (15-70 ind. of coot, Fulica atra L. ha )1 ), abundance of submerged plants was also high with a surface coverage of 70-80%, and benthivorous fish were present, mainly tench, (Tinca tinca L.) and carp, (Cyprinus carpio L.). Exclusion of waterfowl and large fish did not significantly affect the spring growth of pondweed; neither plants growing in situ nor kept in pots. Removal of periphyton from the plants in the pots did not favour growth. The density of macroinvertebrates was not affected by the exclusion of waterfowl and large fish, but it was positively related to aboveground biomass of fennel pondweed. We suggest that even if waterfowl and large fish are in high densities, their effect on fennel pondweed spring growth in lakes with abundant submerged vegetation, such as Lake Mogan, is low.

High level multiple antibiotic resistance among fish surface associated bacterial populations in non-aquaculture freshwater environment

“…Lake Mogan (39 46 0 N, 32 46 0 E) is a large, freshwater shallow lake located in Central Anatolia, 20 km south of Ankara, Turkey (Dogan et al, 2009). This lake also has the status of a Specially Protected Area (SPA), as assigned by the Turkish Ministry of Environment (Sandsten et al, 2005). Mucus samples were collected several times from the fish obtained in different catches.…”

Sazanın (Cyprinus carpio L., 1758) Tatlısu Ekosistemlerine Etkileri İçin Deneysel Kanıt: Türkiye İç Suları İçin Yönetim Yönlendirmeleri Derlemesi

“…In a shallow Turkish lake, exclusion of C. carpio along with other fish species and waterfowl did not significantly affect growth of sago pondweed, nor did it influence benthic invertebrate abundance (Sandsten et al 2005). This lack of significant effects was attributed to the lake's nutrient levels being lower than the threshold level at which herbivory may tip the balance towards the turbid state in cold temperate lakes.…”

“…Only four out of the experiments reviewed were carried out in Turkey, namely those by Beklioğlu et al (2000Beklioğlu et al ( , 2006, Sandsten et al (2005) and Özbay (2008). Based on Vilizzi et al's (2015a) review, this country and, especially, the corresponding risk areas of Thrace and Anatolia (Tarkan et al 2014) were categorised as "low risk" due to C. carpio being semi-naturalised, having low invasiveness, and being the object of overall positive public perception and low scientific concern (Vilizzi 2012; Tarkan et al 2014).…”

Identification and mapping of submerged plants in a shallow lake using quickbird satellite data

“…It is a large and shallow freshwater lake located in Central Anatolia, 20 km south of the capital city Ankara, Turkey. The lake is surrounded by a large emergent plant wetland, which is a nesting, breeding and migratory site for waterfowl species having the status of a Specially Protected Area (SPA), as assigned by the Ministry of Environment (Sandsten et al, 2005). Selected geographical and physical features of Lake Mogan are summarized in Table 1.…”