Review article

Overview of research and scientific findings in the Krka estuary

Damir Viličić orcid.org/0000-0002-2394-4755 ; Sveučilište u Zagrebu Prirodoslovno matematički fakultet, Zagreb, Hrvatska *

* Corresponding author.

Abstract

The Krka River estuary is a unique, internationally recognized natural phenomenon in the karst of northern Dalmatia (Croatia). Nutrient-poor water from the small Krka River enters the sea under narrow tidal range conditions and creates a highly stratified system with a sharp halocline separating brackish and marine layers. Highly stratified estuaries are rare and are found along small Mediterranean rivers. Freshwater phytoplankton entering the estuary from Lake Visovac, a widening of the river, dies in the salinity gradient of the halocline. Suspended particles accumulating in the halocline significantly heat up the halocline in summer. Microbial decomposition of organic matter releases nutrients into the marine layer of the upper estuary, causing a development of marine phytoplankton subsurface blooms. In the lower estuary, phytoplankton blooms are superficial because growth at greater depths is limited by light. The mixing of fresh water and the sea, especially in the halocline (freshwater/seawater interface), dramatically changes the balance of chemical reactions. The halocline is a microlayer in which toxic substances accumulate as well. The cycling of elements is present in the estuary.

Keywords

Krka River; estuary; halocline; research; Adriatic Sea

Hrčak ID:

326922

URI

https://hrcak.srce.hr/326922

Publication date:

2.7.2024.

Article data in other languages: croatian german

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