Risk assessment of non-native fishes in the Balkans Region using FISK, the invasiveness screening tool for non-native freshwater fishes

A high level of freshwater fish endemism in the Balkans Region emphasizes the need for non-native species risk assessments to inform management and control measures, with pre-screening tools, such as the Fish Invasiveness Screening Kit (FISK) providing a useful first step. Applied to 43 non-native and translocated freshwater fishes in four Balkan countries, FISK reliably discriminated between invasive and non-invasive species, with a calibration threshold value of 9.5 distinguishing between species of medium and high risk sensu lato of becoming invasive. Twelve of the 43 species were assessed by scientists from two or more Balkan countries, and the remaining 31 species by a single assessor. Using the 9.5 threshold, three species were classed as low risk, 10 as medium risk, and 30 as high risk, with the latter category comprised of 26 moderately high risk, three high risk, and one very high risk species. Confidence levels in the assessments were relatively constant for all species, indicating concordance amongst assessors

Different aspect of sustainable use of fish resources in Serbia for the period 2006-2017

Ovaj rad ima za cilj da ustanovi koja je uloga zakona u dobrom upravljanju ribolovnim resursima. Zaštita i održivo korišćenje ribljeg fonda u Srbiji regulisano je istoimenim zakonom, a odvija se na 17 ribarskih područja i 29 ribarskih područja u zaštićenim prirodnim dobrima. Na 17 osnovnih ribarskih područja upravljaju „javna preduzeća“ ili privatne firme u statusu „doo“. Kod većih područja, posebno u Vojvodini, postoji više upravljača za jedno ribarsko područje. U zaštićenim prirodnim dobrima upravljači su ujedno i korisnici ribljeg fonda. U periodu od 2006. do 2017. godine Zakon o zaštiti i održivom korišćenju ribljeg fonda menjan je u dva navrata: 2009. i 2014. godine. Podzakonska akta su takođe podložna vrlo čestim promenama. U radu se prate efekti promene zakonske regulative na broj rekre ativnih i profesionalnih ribolovaca, broj ribočuvara i trendove u ulovima. Osnovni trendovi su da broj rekreativnih ribolovaca u navedenom periodu opada, broj profesionalnih riba ra stagnira, dok broj ribočuvara raste. Ulov ima tendenciju opadanja za sve vrste koje se statististički prate (šaran, som, smuđ i deverika od autohtonih vrsta, i babuška i tolstolobik od alohtonih). Odnos ulova u rekreativnom i komercijalnom ribolovu pokazuje značajne promene u poslednjih desetak godina: osim za tolstolobika, kod koga dominira komer cijalni ulov, kod ostalih vrsta je došlo do zamene u smislu da rekreativni ulov preuzima dominaciju u poslednjih nekoliko godin

Risks to stocks of native trout of the genus Salmo (Actinopterygii: Salmoniformes: Salmonidae) of Serbia and management for their recovery

Background. Insufficiently controlled stocking compromises the high diversity of wild trout stocks of Serbia. Native brown trout, Salmo cf. trutta Linnaeus, 1758, and Macedonian trout, Salmo macedonicus (Karaman, 1924), reveal remarkable diversity assessed using the mtDNA molecular markers, with the eight exclusive and several more widely spread haplotypes found in them. Four alien trout species and strains and one strain of Macedonian trout were introduced into the home areas of the native wild trout stocks in Serbia. In addition to them, wild trout stocks were also affected by farmed rainbow trout, Oncorhynchus mykiss (Walbaum, 1792), and brook trout Salvelinus fontinalis (Mitchill, 1815), that regularly escape to streams, and from Ohrid trout, Salmo letnica (Karaman, 1924), and Arctic charr, Salvelinus alpinus (Linnaeus, 1758), stocked into streams and reservoirs. Risk of invasiveness that wild trout stocks are exposed to and their restoration were driving forces for this study. Materials and methods. Trout specimens from the Jerma River sampled in 2013 were additionally analysed for their mtDNA haplotype. The invasiveness potential of eleven alien trout species and strains introduced by stocking into wild brown- and Macedonian trout stocks in Serbia were assessed with the Fish Invasiveness Screening Kit (FISK). Results. Five of introduced trout species and strains were classified as having a high risk (sensu lato) and two of them as having a high risk (sensu stricto) of being (or becoming) invasive. Conclusion. Progressively rising and insufficiently controlled fishing and management with stocking of non-indigenous trout in wild brown trout stocks are the main current threats to the original diversity. Alien brown trout strains cross breed with native brown trout and incorporate into their stocks. Currently, feral rainbow-, brook-, and Ohrid trout reveal great invasive potential by naturalization in waters heavily stocked with them. The fisheries measures aiming to control and/or to eradicate alien strains of brown trout involve the restriction of stocking, landing of trout suspected as of alien strain or species, as well as the stringent control of stocking material used for the restorative stocking. They are mandatory, regarding the conservational dependence of wild brown trout stocks

Group decision support practice ‘as it happens’

Historically, studies of Group Decision Support (GDS) have focused on assessing the degree to which using a GDS makes groups more effective, typically via carefully designed experiments and case study reports. More recently, we have witnessed a growing interest in getting close to GDS practitioners to see how their work is actually done in “real time,” “there-and-then.” What motivates this interest is the recognition that in order to develop better GDS practice we must first pay attention to how it is actually used by those involved in situ. By zooming in on what GDS practitioners actually do with their craft, and the critical role of these doings on generating group outputs and outcomes, a more nuanced understanding of GDS practice can be achieved. Furthermore, this understanding can inform the development of more effective GDS practitioner training and teaching materials. In this chapter we introduce a particular way of studying GDS practice, “as it happens” on the ground, based on ethnomethodology (EM). To illustrate the approach, we provide an example of its application to study GDS practice in a facilitated, computer-supported causal mapping workshop. Overall, the analysis reveals the various ways in which actual GDS practice is accomplished over time, as it happens on the ground, and with what effects. We conclude the chapter by summarizing the distinctive contribution that an ethnomethodologically informed perspective makes to GDS theory and practice, and outlining some potentially useful avenues for future research