Skip to main content
Banner [Small]

Test out our new Bento Search

test area
x
# results
shortcut
Sections
HTML elements
Section Tiles
expand
Tile Cover
Mouse
Math Lab
Space
Tile Short Summary
Math Lab Rooms located in the Main Library in rooms 300X and 300Y
expand
Tile Cover
coffee
CC's Coffee House
Space
Tile Short Summary
Located at the first floor of the LSU Main Library.
expand
Tile Cover
People troubleshooting on a computer
Ask Us
Service
Tile Short Summary
Check our FAQs, submit a question using our form, or launch the chat widget to find help.

Gear

44

FAQ

169

Database Listing

375

Archive Records

41199

Staff

101

Discovery

2065107
Variation in the catch rate and distribution of three important commercial Spanish mackerel (Commerson: Niphonius: Guttatus) related to ENSO events around the waters off Taiwan
Spanish mackerel species are migratory species, also are highly commercially valuable in Taiwan. However, in recent years, climate change and variability have influenced oceanographic conditions, substantially impacting the population dynamics of pelagic species. This study developed weighted habitat suitability index models for three crucial Scomberomorus species—Scomberomorus commerson, Scomberomorus niphonius, and Scomberomorus guttatus—in the waters off Taiwan. Remote sensing data including sea surface temperature, sea surface chlorophyll-a, sea surface salinity, and sea surface height, along with voyage data records that included detailed catch data from Taiwanese drift gillnet fisheries were collected during 2011–2019. The primary fishing grounds for S. commerson are located in the central to southwestern Taiwan Strait, while S. niphonius and S. guttatus are mainly found in the coastal waters off western Taiwan. In autumn, the oceanographic factor preferences are relatively similar among Scomberomorus species, with sea surface temperature being the primary influencing factor. Sea surface height turns to the main influencing factor in winter. Based on the results of the weighted habitat suitability model, we found seasonal differences in habitat preferences and ranges. There is more pronounced overlap in potential habitat in autumn and partial separate condition in potential habitat in winter among Scomberomorus species. Further exploration of the spatiotemporal distribution dynamics of Scomberomorus species under different ENSO periods revealed that during La Niña periods, the potential habitat ranges are broader and extend further south. In contrast, during El Niño periods, and the potential habitat ranges contract northward. Habitat suitable index model may be a useful approach for evaluating possible changes in habitat suitability resulting from climate change or other oceanographic phenomena and in offering suggestions for fishery scientific management.
Significant uncertainty in bark beetle trap catches due to varying pheromone release from dispensers and local trap position
Tree-killing bark beetles are important pests severely affecting forests worldwide. An understanding of their spatio-temporal swarming intensity, typically assessed with pheromone traps, is crucial to guide management actions. While multiple factors have been shown to affect trap catches, we lack knowledge of the effects of inherent dispenser-dependent variations in pheromone release and of local trap position. In a laboratory experiment, we assessed the influence of filling level and temperature on the release rate (Rr) of three commonly used pheromone dispenser products for bark beetles (Pheroprax®, Chalcoprax®, Curviwit®). By conducting a complementary field study at two sites in Germany, we quantified the effect of varying Rr of Pheroprax® and trap position on the number of Ips typographus trapped. Rr of all three products correlated with temperature and strongly declined during the application period in Pheroprax® and Chalcoprax®. In the field, both the temporal variability in filling level and the ambient temperature similarly affected Rr, which in combination led to a fivefold change in trap catches. Additionally, catches varied by a similar magnitude due to local trap position, partly explained by the distance from the forest edge. The large uncertainties found in pheromone trap catches, which may also apply to other pest species, highlight the need for careful interpretation (or correction) of trap data. As a potential improvement of monitoring, we propose swarming models to facilitate more accurate predictions of infestation risk by (i) incorporating uncertainties arising from trap-related factors and (ii) providing continuous information on the spatio-temporal abundance of pest species.