Marine and Freshwater Research
Volume 75
Number 18 2024
Boat-based observations spanning 11 years were used to determine the swimming speed for resting whales in two bays off eastern Australia. Swimming speeds observed in both bays during southward migration were slower than those specified in literature. The effect of location on swimming speed was small, but the swimming speeds of pods with calves and pods without calves present were different in one bay. The importance of management of nearshore environments for effective protection of humpback whales, and the role of swim speeds for assessing humpback whale habitat use are highlighted.
Rigorous monitoring and reporting helps determine the effectiveness of water reforms. The Murray–Darling Basin Plan is a major public policy reform intended to restore water to the environment. We present an independent assessment of the state of the Basin. For 27 indicators, we found that those for the environment were not met and the major benefits were economic, favouring irrigators.
Oceans and marine turtles are facing many challenges. Collaboration and partnership between Traditional Custodians and conservation programs empower Aboriginal young people as future conservation leaders and are important to achieve long-term conservation goals. Three case studies explore the importance of partnerships in conservation, providing additional on-Country opportunities for young people, and enabling future pathways in the Pilbara, Western Australia.
This article belongs to the collection: Science in Sea Country.
Asian sea bass, or barramundi, is a widespread fish widely propagated and highly sought after for food and recreation. We found that the Asian sea bass and barramundi lineage contains three main genetic lineages with numerous subdivisions, and that these divisions are linked to adaptive changes and may be considered evolutionarily significant. These findings indicate diversity within Asian sea bass and barramundi that may be useful for both conservation and exploitation.
Glacier melting as a result of climate change poses a significant threat to global freshwater reserves. As glaciers retreat, regions dependent on glacier-fed rivers face risks of water scarcity, altered river flows and increased vulnerability to natural disasters. This study has highlighted the urgent need for climate-mitigation strategies to preserve freshwater resources and prevent widespread environmental and societal impacts.
We used aerial imagery to survey the distribution and abundance of intertidal pools created by stingrays in Quandamooka (Moreton Bay), Australia. These pools are nurseries for the juveniles of commercially important fish and prawns. Higher pool densities were found in areas with mangroves positioned in the high shore, indicating that these areas might be more important than others as nurseries.
The association of fish larvae and juveniles with aquatic macrophytes was investigated in a cascade of small hydroelectric power plants. We collected 29 taxa and used macrophyte banks for their initial development. We demonstrated that these habitats are important for the conservation and management of the local fish fauna, mainly because of the absence of typical nursery areas (tributary mouths, marginal lagoons).
This article belongs to the collection: Ecological monitoring and assessment of freshwater ecosystems: new trends and future challenges.
Algal bloom is a global public environmental issue. Lakes and reservoirs are prone to algal blooms because of their relatively static water flow. In the drinking-water source reservoir with low concentrations of nitrogen and phosphorus, there will still be seasonal algal outbreaks, in which light intensity and temperature are important factors affecting algal growth.
This article belongs to the collection: Ecological monitoring and assessment of freshwater ecosystems: new trends and future challenges.
Macrobrachium vollenhoveni is a freshwater prawn native to Africa. Gonadal maturation begins in March, peaks in July, and spawning occurs from July to October, aligning with the rainy season. Females reach sexual maturity at a larger size than do males. The species is characterised by high fecundity.
Fishing and industrial activities affect global fish populations. Cockburn Sound near Perth, Australia, a key spawning site for Chrysophrys auratus (pink snapper), faces risks from new shipping development. This study tests a cost-effective method using drones and fish finders to track these fish. The approach successfully mapped fish aggregations and could aid in evaluating environmental impacts and managing resources.
The invasive wels catfish is spreading to many European waterbodies. The objective of the study was to investigate its life-history traits (growth and reproduction) for the first time in southern France. Culling was used to assess the key life-history traits, using sections of pectoral spines for age and growth estimations, and gonad macroscopic examination for the reproduction parameters. The life-history parameters (rapid growth, early maturation, high fecundity) showed a very high potential for adaptation and colonisation.
The inter-provincial panel data of China’s Yangtze River Delta from 2011 to 2020 were utilised, and quantitative analysis was conducted on the pollution- and carbon-reduction subsystem of the Yangtze River Delta on the basis of the composite-system co-ordinated-degree model, evaluating the order degree, internal co-ordinated degree, and composite-system co-ordinated degree, according to which we came to the relevant conclusions.
This article belongs to the collection: Ecological monitoring and assessment of freshwater ecosystems: new trends and future challenges.
This paper is a first-hand attempt to explore the phytoplankton pigment composition and community structure during the pre-monsoon season (April) of 2019 in the yet underexplored regions of the Indian Ocean, i.e. western, and central Bay of Bengal. High-performance liquid chromatography derived marker pigments and pigment ratios, CHEMTAX analysis and microscopy were used to classify phytoplankton into various groups. The outcomes of the study could provide accurate baseline data for biogeochemical modelling of the ecosystem with better predictability.
Manta rays and zebra sharks act as major drawcards for ecotourism businesses. Modelling was used to predict changes to migration patterns for these species at popular dive locations in New South Wales. These models indicated that seasonal migrations are likely to be altered by future ocean warming, potentially increasing opportunities to interact with these species by up to 4 months by mid-century.
Sexual selection drives the individual’s life history, leading to the development of alternative mating tactics or even bizarre sexual traits to maximise fitness. In this study, we investigated the mating behaviour and the role of a secondary sexual trait of the Mediterranean killifish (Aphanius fasciatus) highlighting its role as an excellent model for studying polyginandrous mating systems.
, J. de Bie 
