Search

Non-indigenous species (NIS) can impact marine biodiversity and ecosystem structure and function. Once introduced into a new region, secondary dispersal is limited by the physiology of the organism in relation to the ambient environment and by complex interactions between a suite of ecological factors such as presence of predators, competitors, and parasites. Early prediction of dispersal potential and future ‘area of impact’ is challenging, but also a great asset in taking appropriate management actions. Aerobic scope (AS) in fish has been linked to various fitness-related parameters, and may be valuable in determining dispersal potential of aquatic invasive species in novel environments. Round goby, Neogobius melanostomus, one of the most wide-ranging invasive fish species in Europe and North America, currently thrives in brackish and fresh water, but its ability to survive in high salinity waters is unknown to date. We show that AS in round goby is reduced by 30% and blood plasma osmolality increased (indicating reduced capacity for osmoregulation) at salinities approaching oceanic conditions, following slow ramping (5 PSU per week) and subsequent long-term acclimation to salinities ranging between 0 and 30 PSU (8 days at final treatment salinities before blood plasma osmolality measurements, 12–20 additional days before respirometry). Survival was also reduced at the highest salinities yet a significant proportion (61%) of the fish survived at 30 PSU. Reduced physiological performance at the highest salinities may affect growth and competitive ability under oceanic conditions, but to what extent reduced AS and osmoregulatory capacity will slow the current 30 km year-1 rate of advance of the species through the steep salinity gradient from the brackish Baltic Sea and into the oceanic North Sea remains speculative. An unintended natural experiment is in progress to test whether the rate of advance slows down. At the current rate of advance the species will reach the oceanic North Sea by 2018/2019, therefore time for taking preventative action is short. [ABSTRACT FROM AUTHOR]

The round goby (Neogobius melanostomus ; Pallas, 1814) is one of the most widespread invasive fish species. It originates from the Black Sea and the Sea of Azov but has un-intentionally been introduced to fresh and brackish water bodies on both sides of the Atlantic. Small-scale fishermen catch large amounts of the invasive round goby as the species continues to spread and populate new areas of the Baltic Sea. We were concerned with the possibilities for a "use and reduce" solution to the round goby invasion. However, to capture the interest of restaurants, supermarkets, and distributers, more information about seasonality in product supply and nutritional quality is needed. We therefore studied a round goby bycatch fishery in the Western Baltic Sea (Denmark) and describe the seasonal dynamics in catch rates, size distribution, condition factor, lipid and protein content, fatty acid profile, and meat texture. We found that while the catch rates peaked in spring, lipid content and meat texture improved significantly, later in the year. Protein content also peaked in late summer and fall, but it was only marginally higher compared to spring. We compare the results to relevant species and conclude that round goby is a relatively lean fish all year (only slightly fatter than for example cod). The firmness of the meat in fall, resembles farmed trout and it has a highly favorable fatty acid composition, reflected by a low n-6 to n-3 ratio. The main bottleneck related to the introduction of round goby to the consumer market is likely going to be the small size. [ABSTRACT FROM AUTHOR]