Observations of the biological communities at Bolsa Chica artificial reef

Bolsa Chica Artificial Reef (BCAR) was constructed in November 1986 with 10,400 tons of concrete rubble and eight concrete and steel barges. Prior to any additional augmentation of BCAR, the u.s. Army Corps of Engineers and the California Coastal Commission required the California Department of Fish and Game (CDFG) to survey the bioloqical communities on and around BCAR. In April 1992, qualitative surveys of the biological communities were conducted on one of the eight modules at BCAR and at a nearby sand-only site. One of the modules, Module D, located in 90 feet of water (MLLW), was surveyed for fish, macroinvertebrates, and turf community organisms (small plants and sessile animals). Twelve species of fish were observed, including kelp bass (Paralabrax clathratus) and barred sand bass (P. nebulifer). Eight macroinvertebrate species were observed, rock scallops (Crassedoma giganteum) being the most abundant. The turf community was comprised of thirteen invertebrate taxa, among which erect ectoprocts (Bugula spp.) were the most numerous. Two species of foliose red algae (Rhodymenia pacifica and Anisocladella pacifica) were also observed. The reef has reached an advanced stage of successional development with fish and invertebrate communities diverse and well established. However, due,.to its depth and the turbidity of surrounding waters, this reef is not likely to ever support a diverse algal community. The diversity and abundance of fish and macroinvertebrates were, as to be expected, much lower in the nearby sand-only site. Only two species of fish and seven macroinvertebrate species were observed. Of these, only the sea pen, Stylatula elongata, was common. Overall, when compared to nearby sand-only habitats, Bolsa Chica Artificial Reef appears to contribute substantially to the local biological productivity. In addition, the concrete rubble used in BCAR' s construction appears to be performing as well as the quarry rock used in all of CDFG's experimental reefs. (Document pdf contains 22 pages)

A report of biological observations at Pacific Beach artificial reef, Oceanside artificial reef, and Santa Monica Bay artificial reef

(Document pdf contains 16 pages)

A report of biological observations at Oceanside #1 and #2 artificial reefs, Carlsbad artificial reef, Pacific Beach artificial reef, and Mission Bay Park artificial reef

(Document pdf contains 22 pages)

Pendleton Artificial Reef: annual progress report presented to Southern California Edison Company

(PDF contains 82 pages.)

Cooperative artificial propagation programs for salmon and steelhead, 1995-1996

Fifteen cooperative fish rearing and planting programs for salmon and steelhead were active from July 1, 1995 through June 30, 1996. For all programs, 134,213 steelhead trout,(Oncorhynchus mykiss), 7,742,577 chinook salmon,(~ tshawytscha),and 25,075 coho salmon(~ kisutch) were planted. (PDF contains 26 pages.)

Cooperative artificial propagation programs for salmon and steelhead, 1996-1997

Fourteen cooperative fish rearing and planting programs for salmon and steelhead were active from July 1, 1996 through June 30, 1997. For all programs, 208,922 steelhead trout, (Oncorhynchus mykiss), 10,334,457 chinook salmon,(O. tshawytscha),and 60,681 coho salmon(O. kisutch) were planted. (PDF contains 24 pages.)

Preliminary investigation on growth responses of Cyprinus carpio L. fed on locally formulated artificial diets

The growth rate and feed conversion ratios of the common carp, Cyprinus carpio were measured for five test diets in 14-day replicate laboratory studies. The young carp were fed with artificial test diets with crude protein contents ranging from 14.50 to 21.42 per cent. Within this range of feed characteristic optimum growth rates were obtained with diets containing 20.25 and 21.42 per cent crude protein. The study of the effect of varying ration levels showed that growth rates increased with increases of ration size, but the food conversion efficiency and protein efficiency ratios decreased markedly as ration size was increased

Growth responses and yield of heterotis (Heterotis niloticus) on artificial diet

The growth responses and yield of Heterotis niloticus on artificial diets of varying protein levels were studied in a bid to assess the implication of feeding Heterotis in intensive fish production venture for a rearing period of 84 days. One hundred and twenty juvenile H.niloticus were fed for 12 weeks on 28%, 31%, 34% and 37% dietary crude protein levels. The fish were reared in 4 concrete tanks stocked at the rate of 10 fish per M super(2) 100,00/hectare). Consequently, the weight gain, food conversion ratio, serum protein and albumin-globulin ratio were determined to assess the growth and state of health of the fish. The yield was appraised through economic considerations of cost of production of fish and diets (feed). The varying crude protein levels significantly influenced mean weight gain, percentage weight gain and food conversion ratio however, the 37% crude protein in diet produced the best growth. The serum protein was highest in fish raised on 31% crude protein diet while the highest value was recorded for albumin-globulin ratio on diet containing 34% crude protein. The yield from treatments 1, 2, 3, and 4 were 114.38 of/84 days 571.9kg/g hect);146.79g/84 days 733.95kg/hect), respectively. However, treatment 3 recorded the highest value for profit index

Commercial production of Clarias fry and fingerlings in indoor and outdoor concrete tank systems

Induced breeding technique by hypophysation is being applied at the Kainji Lake Research Institute Fisheries Division Hatchery complex in New Bussa, Nigeria, for the production of Clarias fry and fingerlings in indoor and outdoor concrete tank systems. The hatchlings are fed on livefood (zooplankton) and artificial feed. Source of zooplankton is from cultured stock which is maintained throughout the breeding season by fertilization. Production values show that an average of over 4,000 hatchlings (larvae) can be produced by a female breeder (over-700g wt) and percentage survival after two months ranges between 70 to 75%. With the proposed modification and expansion project, an estimated production of over 0.5 million fingerlings per breeding season is projected

Aspects of the fishing industry and an overview of artificial reefs and fish aggregating devices for increasing fisheries output and viability in Nigeria

Aspects of the Nigerian fishing industry are outlined to explain the concept of fishing systems viability which is often influenced by a combination of factors including biological productivity, as well as technical, economic and social factors. The productivity of the aquatic environments can be increased by the construction and installation of artificial reefs and fish aggregating devices. These man-made structures provide shelters, food and breeding grounds for fin fish and shell fish. The habitat enhancement techniques are appropriate, efficient, cheap and simple strategic options for increase in fish production. Recommendations for effective utilization and long term management are outlined.

The effects of Moina artificial diet and nutrase xyla supplemented artificial diet on growth and survival of Clarias gariepinus larvae

An experiment was carried out to investigate the effects of Moina, artificial diet (55% CP) and nutrase xyla supplemented artificial diet on growth performances and survival rates of Clarias gariepinus larvae. A combination of Moina and artificial diet (with or without nutrass xyla) resulted in higher growth performance and survival rates during a 12-day nursing time with specific growth rates of 30.04-32.15% d super(-1) and survival rates of 87.5-90%. Best growth performance and survival rate was obtained with a combination of Moina and artificial diet supplemented with nutrias xylem. Feeding of Moina and artificial diet supplemented, with nutrias xyla alone to the larval led to a lower growth performance of 25.60-27.04% d super(-1). However, the survival rate of Monia of larvae fed a combination of Moina and artificial diet (with or without nutrias xylem supplementation) artificial diet without nutrias xylem addition proved relatively less suitable for larval rearing of Clarias gariepinus owing to a low survival rate of 69% and growth performance of 19.7% d super(-1). This study showed the feasibility of feeding a combination of Moina and nutrias xylem supplemented artificial diet to the larvae of Clarias gariepinus

Use of Artificial Eelgrass Mats by Saltmarsh-Nesting Common Terns (Sterna hirundo)

Terns and skimmers nesting on saltmarsh islands often suffer large nest losses due to tidal and storm flooding. Nests located near the center of an island and on wrack (mats of dead vegetation, mostly eelgrass Zostera) are less susceptible to flooding than those near the edge of an island and those on bare soil or in saltmarsh cordgrass (Spartina alterniflora). In the 1980’s Burger and Gochfeld constructed artificial eelgrass mats on saltmarsh islands in Ocean County, New Jersey. These mats were used as nesting substrate by common terns (Sterna hirundo) and black skimmers (Rynchops niger). Every year since 2002 I have transported eelgrass to one of their original sites to make artificial mats. This site, Pettit Island, typically supports between 125 and 200 pairs of common terns. There has often been very little natural wrack present on the island at the start of the breeding season, and in most years natural wrack has been most common along the edges of the island. The terns readily used the artificial mats for nesting substrate. Because I placed artificial mats in the center of the island, the terns have often avoided the large nest losses incurred by terns nesting in peripheral locations. However, during particularly severe flooding events even centrally located nests on mats are vulnerable. Construction of eelgrass mats represents an easy habitat manipulation that can improve the nesting success of marsh-nesting seabirds.

Aspects of the washout of salmonid eggs. 1. Observations on the physical characteristics of real and artificial eggs, their rate of fall in a water column and their pattern of settlement in an experimental channel

When salmonid redds are disrupted by spates, the displaced eggs will drift downstream. The mean distance of travel, the types of locations in which the eggs resettle and the depth of reburial of displaced eggs are not known. Investigation of these topics under field conditions presents considerable practical problems, though the use of artificial eggs might help to overcome some of them. Attempts to assess the similarities and/or differences in performance between real and artificial eggs are essential before artificial eggs can validly be used to simulate real eggs. The present report first compares the two types of egg in terms of their measurable physical characteristics (e.g. dimensions and density). The rate at which eggs fall in still water will relate to the rate at which they are likely to resettle in flowing water in the field. As the rate of fall will be influenced by a number of additional factors (e.g. shape and surface texture) which are not easily measured directly, the rates of fall of the two types of egg have been compared directly under controlled conditions. Finally, comparisons of the pattern of settlement of the two types of egg in flowing water in an experimental channel have been made. Although the work was primarily aimed at testing the value of artificial eggs as a simulation of real eggs, several side issues more directly concerned with the properties of real eggs and the likely distance of drift in natural streams have also been explored. This is the first of three reports made on this topic by the author in 1984.

Experiments using an artificial stream to investigate the seasonal growth of chalk-stream algae

Research into the production ecology of chalk streams using a large artificial recirculating stream is described. Physical chemical processes including calcium and inorganic phosphate levels, and exchange of gaseous carbon dioxide in both a simple closed system and a circulating system with gravel substrate have been monitored in both light and dark conditions. Further experiments were concerned with the seasonal changes in algal growth over the gravel substrate with constant water velocities and replenishment. The algal population, composed mainly of the diatoms Achnanthes minutissima, Meridion circulare, Nitzschia fonticola and Synedra ulna reached a peak in mid May and declined rapidly during June. Concentrations of phosphate phosphorus fell as the diatoms grew but was not thought to limit growth. Silicate concentrations followed the diatom cycle closely but never fell below 0.8 mg/l Si. It is possible that one of the nutrients may have been limiting the rate of growth due to steep diffusion gradients through the algal mat. In the last summer and autumn a hard calcareous crust composed of the green alga Gongrosira incrustans and the blue green alga Homeothrix varians , developed. The channel stream is compared with the natural conditions found in chalk streams.

Survival and Growth of American Alligator (Alligator mississippiensis) hatchlings after artificial incubation and repatriation

Hatchling American Alligators (Alligator mississippiensis) produced from artificially incubated wild eggs were returned to their natal areas (repatriated). We compared artificially incubated and repatriated hatchlings released within and outside the maternal alligator’s home range with naturally incubated hatchlings captured and released within the maternal alligator’s home range on Lake Apopka, Lake Griffin, and Orange Lake in Florida. We used probability of recapture and total length at approximately nine months after hatching as indices of survival and growth rates. Artificially incubated hatchlings released outside of the maternal alligator’s home range had lower recapture probabilities than either naturally incubated hatchlings or artificially incubated hatchlings released near the original nest site. Recapture probabilities of other treatments did not differ significantly. Artificially incubated hatchlings were approximately 6% shorter than naturally incubated hatchlings at approximately nine months after hatching. We concluded that repatriation of hatchlings probably would not have long-term effects on populations because of the resiliency of alligator populations to alterations of early age-class survival and growth rates of the magnitude that we observed. Repatriation of hatchlings may be an economical alternative to repatriation of older juveniles for population restoration. However, the location of release may affect subsequent survival and growth.