Nutrient digestibility of angling baits for carp, Cyprinus carpio, with implications for groundbait formulation and eutrophication control

Abstract

To evaluate the suitability of angling groundbaits as a fish feed and the potential for nutrient loss, the macronutrient digestibility of four groundbaits was investigated in carp, Cyprinus carpio L., using a sieving method of faeces collection and chromic oxide. Apparent digestibility coefficients (ADCs) of protein and lipids were >80% for all angling baits. ADCs of nitrogen-free extracts and phosphorus (P) differed significantly between the test diets, probably because of divergent feed compositions and ingredient treatments. The generally high digestibility estimates indicated that fish feeding on angling groundbait will benefit from this food source. The differences in nutrient digestibility suggested that type of groundbait and ingredient used will have a major effect on potential eutrophication and fish production caused by groundbaiting. The principle of groundbaits to protect the environment should be to minimise the P-content of the groundaits and maximising P-digestibility and P-retention efficiency. K E Y W O R D S :Fisheries Management and Ecology, 2005, 12, 91-97

Modeling water quality in reservoirs used for angling competition: Can groundbait contribute to eutrophication?

“…Although some studies have addressed groundbaiting (e.g., Wolos et al 1992, Niesar et al 2004, Arlinghaus and Niesar 2005, Lewin et al 2006, we found no previous research that applied the modeling of reservoir water quality with simulations related to groundbaiting. We integrated SWAT (Neitsch et al 2002) …”

“…Ordinary commercial groundbait is composed mainly of flours (e.g., corn, peanut, wheat), bread crumbs and crackers, aromatics, and dyes, in different proportions depending on the target species. Some studies indicate that the use of groundbait can negatively affect water quality and trophic status, cascading to other ecosystem components such as invertebrates (Wolos et al 1992, Niesar et al 2004, Arlinghaus and Niesar 2005, Lewin et al 2006. Nutrient enrichment of waterbodies and the consequent eutrophication effects are major problems for water quality in reservoirs (Smith et al 1999, Carpenter andLathrop 2008).…”

Angling baits and invasive crayfish as important trophic subsidies for a large cyprinid fish

“…revealed that the growth, density and fitness of the invasive fish, Pseudorasbora parva, was enhanced in pond mesocosms that received trophic subsidies in the form of small fishmeal pellets, with this often being an indirect mechanism as the elevated nutrient concentrations that occurred as a result of pellet introduction had the effect of increasing rates of algal standing stocks. Whilst the quantity of fishmeal pellets that were introduced into each river was not quantified, for comparative purposes it has been estimated that recreational anglers in Germany introduced a total of 24,000 tonnes of angling bait into freshwater fisheries in 2004 (Arlinghaus and Niesar 2005). This was not only believed to represent a significant trophic subsidy for the fish, but also elevated nutrient concentrations in the water and subsequently impacting adversely on water chemistry (Niesar et al 2004;Arlinghaus and Niesar 2005;Lewin et al 2006).…”

“…Nevertheless, pellets are increasingly being used by freshwater anglers in Europe as both an attractant and hook-bait to target fish of the Cyprinidae family, such as common carp Cyprinus carpio and European barbel Barbus barbus . Moreover, the quantities used can be substantial, with the amount of bait used annually per angler in Germany esti-mated at 7.3 kg (Arlinghaus and Niesar 2005). Given that these pellets were originally designed for feeding carniv-orous fish in aquaculture to maximise their growth through the input of an energy rich resource that is relatively easy to assimilate (Naylor et al 2000), then this at least partially explains their effective use within freshwater angling for a range of omnivorous and carnivorous species.…”

“…Trophic subsidies that originate from fishery activities can provide recipient aquatic communities with alternative food resources that are energy rich and highly nutritious (Grey et al 2004;Arlinghaus and Niesar 2005;FernandezJover et al 2011a, b), such as pelletized fishmeal that are usually high in protein (from fishmeal) and lipid (from fish oil) (Naylor et al 2000). Whilst it was recently estimated that the global annual production of fishmeal pellets was 3.7 million tonnes (Tacon and Metian 2008), only a small proportion of this production is used directly as bait for recreational angling.…”