Summary
The contemporary tackle box for recreational angling is packed with lures that cover the full spectrum of colours with the assumption that colour influences fishing success. Yet, there is little research that identifies how lure colour might influence capture rates or size-selectivity. Moreover, while much is known about the factors that influence hooking injury or hooking depth (which is a good predictor of mortality in released fish), to our knowledge no studies have examined if such factors are influenced by lure colour in fishes. Here we tested the effects of lure colour on catch-per-unit-effort (CPUE), size-selectivity and hooking injury of largemouth bass, Micropterus salmoides, using artificial 12.7 cm un-scented soft-plastic worms. Lures comprising six colours in three colour categories (i.e., dark – bream ‘blue’, leech ‘black’; natural – cigar ‘red’, wasp; bright – pearl ‘white’, sherbert ‘orange’), which were individually fished for 20-min intervals multiple times per day. Data analysis revealed that CPUE was similar across individual colours and categories. However, bright colours appeared to selectively capture larger fish than either dark or natural lure colours. Lure colour did not influence length-corrected hooking depth or anatomical hooking location. Our study reveals that while different lure colours might capture the imagination and wallet of the angler, they do not influence CPUE or hooking injury in bass but appear to have a small influence on the size of captured fish.
Methodology
Largemouth bass were caught using artificial 12.7 cm un-scented soft-plastic worms in six colours representing three colour categories (i.e., dark – leech ‘black’, bream ‘blue’; natural – cigar ‘red’, wasp; bright – sherbert ‘orange’, pearl ‘white’); a medium-action spinning rod and reel with braided line (6 kg breaking strength), and size 1 octopus hooks. The soft-plastic lures were fished quite passively where they were cast out and left to slowly sink at which time the angler would pick up the slack line and then slowly bring the lure back to the boat. Nearly all fish took the lure on the fall rather than the retrieve. The anglers (N = 8) were considered to be intermediate in experience. Each lure colour was fished for 20-min intervals. Fishing all six colours for a 20-min interval by an individual angler was referred to as a cycle and an entire cycle was completed before a previously fished lure colour was fished again. After a cycle was completed each participating angler started the new cycle with a different lure colour than they had used in the previous cycle. We did not record “angler” or use it as a factor in the analysis because it was randomized and each angler completed entire cycles. Each largemouth bass caught was processed as follows. First, the lure colour and size of the fish (total length in mm) were recorded. Next, hooking depth was measured from the tip of the nose to the location of hook insertion (as per Cooke et al., 2001; mm) and anatomical hooking location was recorded. Hooking locations were standardized by classifying them as shallow or deep; shallow hooking was considered to include upper jaw, lower jaw, and corner, and deep hooking was considered to include; roof, gullet, and tongue. Next we qualitatively assessed bleeding at the hook wound site as being present or absent, if bleeding was present it was classified as (A) ‘some bleeding’ or (B) ‘lots of bleeding’. At time of release we assessed whether the fish was able to maintain equilibrium as an indicator of fish condition (Davis, 2010) and as a predictor of post-release mortality (Raby et al., 2012). We also noted any immediate hooking mortality and if the fishing line needed to be cut to release the fish given that the hook placement was too deep to safely remove with pliers.
Largemouth bass were caught from all around Lake Opinicon with a particular focus on littoral areas, with occasional fishing taking place in the deeper pelagic waters near the middle of the lake. Fishing took place each day (rain or shine) and only ceased in the presence of lightning/thunder, with fishing being resumed when the lightning/thunder ceased. Fishing occurred from approximately dawn to dusk each day.