No abstract

Effective management of recreational fisheries requires information on fine-scale spatial patterns of recreational exploitation. Such information is particularly important for specially designated regions such as recreationalonly fishing areas (ROFAs). Using data acquired through progressive counts and interview-based surveys, this study quantitatively compared recreational effort, harvest-per-unit-effort (HPUE) and species composition among zonal habitats in three representative estuarine ROFAs in eastern Australia. The zones compared were as follows: (1) entrance channels;(2) lake areas; (3) artificial reefs; (4) tributary creeks; (5) rivers; and (6) canals. In most cases, effort was concentrated in the lake zones, which had the greatest access to fisheries resources. The lake and channel zones were associated with some of the highest HPUEs for key taxa [Acanthopagrus spp. (hybrid complex of Acanthopagrus butcheri (Munro) 9 Acanthopagrus australis (Owen)), Platycephalus fuscus (Cuvier), Sillago ciliata (Cuvier) and Girella tricuspidata (Quoy & Gaimard)] and a greater number of highly sought-after species. Drawing on specific examples from these findings, this paper concludes by illustrating how spatial information on exploitation gained from this type of research can be used to meet the fundamental goals of recreational fisheries management at fine spatial scales. K E Y W O R D S :ANOSIM, creel surveys, fisheries management, generalized linear models, recreational fishing, recreational fishing havens.

The eastern rock (spiny) lobster, Jasus verreauxi occurs along the east coast of Australia and North Island of New Zealand. The resource off New South Wales (NSW), Australia, is managed through a suite of input controls and individual catch quotas. The stock assessment process has identified that the length-based model used in annual stock assessments would be improved with more precise information about the species' growth patterns. This study provides the first published information on a growth model for this species by describing the results of tagging experiments from 1995 to 2001 (inclusive). Lobsters were tagged with anchor tags across six locations spanning the main distribution of the species off NSW. The maximum time that a tagged lobster was at liberty was 2573 days. Recapture data were fitted to the von Bertalanffy growth function (VBGF) using Fabens method, including parameters for seasonal growth and individual variability in growth, and extraneous information about the average length and age of puerulus larvae so that the parameter t 0 could be calculated. Males had a longer predicted mean growth increment at 98 mm antennal carapace length (CL) and 202 mm (CL) (g α and g β , the two input sizes used in the model) than females. Transformed values (with CI) for the VBGF parameter K were 0.13 (0.12-0.16) and 0.14 (0.12-0.15) for females and males, respectively. Respective values for the VBGF L xj were 239.77 (224.37-243.51 mm CL) and 246.10 (244.69-280.70). The eastern rock lobster is amongst the largest of the palinurid family. The species is exploited for approximately 4 years before reaching sexual maturity (approximately 8 years of age) and for approximately 3 years after that time until the legal maximum length is attained. These exploitation circumstances expose this longlived species (approximately 30 years) to the risk of recruitment overfishing and consequently this risk is assessed annually through a stock assessment process.

The present study investigated the long-term (>2 years) site fidelity, residency and movement patterns of Acanthopagrus australis (Sparidae) at artificial (AR) and natural reef (NR) sites. Acoustic telemetry was used to assess movement patterns of 39 fish released at NR and AR locations and other habitat types within the study area. Detection periods ranged from 1 day to a maximum of 912 days, with 36% of fish detected by the array for >1 year and a further 7% detected for >2 years. Results indicate that tagged fish tended to remain associated with the release site; however, AR fish were detected for considerably longer periods with greater numbers of fish identified as resident within the AR system. AR-released fish were also identified more frequently across the entire array, with the majority (90%) of detections between receiver stations located within the AR system. Results were affected by short detection periods (<6 days) of a relatively high proportion of fish released at the NR, possibly indicating differential rates of fishing mortality between locations. Longer range movements of >200km were also detected, but there was no obvious trend with release location. The results of the present study indicate interactions between existing and introduced artificial habitat are more complex than a ‘draw-down’ effect and provide further evidence that AR systems provide suitable habitat for a variety of species, as well as further support for the use of AR systems in fisheries enhancement initiatives. The results also have important implications for understanding the effect of AR systems and indicate that the size of the reef system may be an important factor in controlling for levels of fishing-related mortality.

The behaviour of coastal fishes to new habitats and trophic opportunities provided by artificial reefs may reveal the key processes which sustain fish production at these reefs. We quantified the trophic link between benthic predators and pelagic forage fish from the movement and foraging behaviour of an ambush predator, the bluespotted flathead Platycephalus caeruleopunctatus, around an artificial reef in relation to schools of small pelagic fish. We used a network of acoustic receivers to monitor the fine-scale movements of 48 acoustically tagged flathead around 5 groups of artificial reef modules for 8 mo in conjunction with acoustic surveys of pelagic baitfish and sustained monitoring of current speed and direction. Flathead were highly associated with the artificial reef, with 44% of detections within 10 m of the modules. Flathead had a considerable degree of fidelity to the reef system, with an average residency period of 84 d yr-1 (residency index = 0.23, SD = 24 d). Low activity was recorded by accelerometers in the north-east of the artificial reef. This coincided with high densities of forage fish which were also found inside the stomachs of the flathead. Artificial reefs with high vertical relief allow planktivores to feed through more of the water column, fixing more pelagic biomass into the system. Defining the residency and trophic connectivity of fish at artificial reefs is critical to clarify the production-attraction debate and the sustainability of fishing at artificial reefs.