Ecological features and cultivation potential of the remaining populations of Gongolaria barbata (Stackhouse) Kuntze on the Istrian coast

Bilajac, Andrea (2024) Ecological features and cultivation potential of the remaining populations of Gongolaria barbata (Stackhouse) Kuntze on the Istrian coast. Doctoral thesis, Institut Ruđer Bošković Zagreb.

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Abstract

Gongolaria barbata is a brown macroalgae that was once a key habitat builder on the Istrian coast. Today, its distribution is limited to a few habitats: the shallow infralittoral zone, mediolittoral pools, and a coastal lagoon. This study mapped G. barbata populations on the western coast of Istria, analyzing morphometric characteristics and biomass at selected locations to assess the remaining populations. Recent data were compared with historical data to identify long-term changes and develop a general biomass prediction model based on morphometric traits. The lagoon population potentially represents the last continuous forest on the Istrian coast, despite extreme summer temperatures. To explore this, an ex situ thermotolerance experiment was conducted, testing the effect of elevated temperatures on adult individuals from the lagoon. Ex situ cultivation under different light intensities, as well as in situ growth and development of juvenile individuals over a year with abiotic factor monitoring, was investigated to optimize restoration methods. Results showed significant variability in G. barbata within and between locations, with some populations showing long-term degradation trends. While a general biomass prediction model is feasible, seasonal sampling is required for accuracy. Adult individuals demonstrated resilience and regeneration after prolonged exposure to extreme temperatures. Cultivation of G. barbata is possible under controlled ex situ conditions and in favorable in situ abiotic conditions, which support optimal growth of juveniles. These findings contribute to our understanding of the ecology, restoration potential, and conservation of one of the most important habitat-forming species in the Mediterranean.

Item Type:

Thesis (Doctoral thesis)

Uncontrolled Keywords:

Gongolaria barbata; morphometry; biomass prediction; thermotolerance; cultivation; restoration

Subjects:

NATURAL SCIENCES > Interdisciplinary Natural Sciences > Marine Science

Divisions:

Center for Marine Research

Projects: