Abstract: A process for making a rigid pipe with the aid of flexible parallel coextensive skins interiorly filled with a catalyst-curable flexible filler, where the flexible skins and filler are laid along any desired surface contour and then the interior space within the inner skin is expanded to form the pipe and catalyst is introduced through one or both of the skins which is catalyst-permeable, to produce a rigidized pipe.

Abstract: This disclosure is concerned with improvements in releasing fresh-water salmon smolt and the like into the sea following periods of salt-water imprinting and maturation in the region of desired sea-return.

Abstract: This disclosure is concerned with novel cover arrangements for providing dark stacking and rest areas in confined water volumes for fish growth acceleration, including salmonoids and the like, and involving pluralities of closely spaced covers contacting the water and providing successive dark areas while influencing water circulation by the edges of the covers to swirl feed thereat; forms of these arrangements being adapted both for land-constructed pools or ponds, and confined effective pool or pond volumes in the sea constructed as netted sea cages bordered by floating or exposed walkways and the like.

Abstract: A novel seal around conduits passed through walls of fluid-containing housings embodying a stretchable annular butyl-rubber-like sheet washer stretch-fitted upon the inner end of the conduit and conformed to the inner wall portion of the housing around the conduit and held there-against by the pressure of the fluid against the washer irrespective of the contour or irregularities or material of the inner wall surface.

Abstract: This disclosure is concerned with the very shallow-water holding the live fish on flat trays in a dry oxygen-saturated atmosphere to obviate the requirement of large volumes of water, and special compartments, especially, though not only, in transport applications.

Abstract: This disclosure is concerned with novel cover arrangements for providing dark stacking and rest areas in confined water volumes for fish growth acceleration, including salmonoids and the like, and involving pluralities of closely spaced covers contacting the water and providing successive dark areas while influencing water circulation by the edges of the covers to swirl feed thereat; forms of these arrangements being adapted both for land-constructed pools or ponds, and confined effective pool or pond volumes in the sea constructed as netted sea cages bordered by floating or exposed walkways and the like.

Abstract: This disclosure is concerned with applications of the discovery that the normal reversion of fresh-water-developed sea-type salmon smolt back to parr, usually within several weeks of smolting, can be prevented, and at the very least significantly retarded, by not removing the smolt to salt water, but by maintaining the same in dark volumes of fresh water with external contrastedly illuminated feed zones(s) to hold the fish in a continual smolt condition with continuing growth and without reversion to parr characteristics; and in some applications, effectively rapidly converting sea-type salmon to, or imbuing the same with, land-locked salmon characteristics.

Abstract: This disclosure is concerned with utilizing the lower dark strata of deep sea cages and the like for fish, such as salmon, as a stress-relief resting volume, while providing specially contoured artificial illumination beyond daylight hours that is limited to upper strata of the cages where feed is periodically applied, and which illumination is prevented from penetrating into the dark strata, but rather provides a predetermined upper laterally illuminated feed-exposing strata, viewable diffusely from below by the fish in the dark lower resting strata.

Abstract: This disclosure is concerned with creating relatively darkened or light-shielded coverings along and upon a substantial selected area of the surface of a pond or other confined fish-holding water volume in the form of surface turbulence generated over said selected area by water spraying or other agitation, with calm illuminated feed zones adjacent but external to said selected area.

Abstract: This disclosure relates to novel portable walk-way constructions for ready application and withdrawal over floating and other covers extending over considerable areas of fish-farming ponds and the like and having internal openings, the construction enabling manipulation from outside the outer walls of the pond, preferably by pivotal and sliding engagement with the top of the outer wall, or the cover, or both, and preferably with the aid of a strand attached to the lower region of a terminal leg structure depending from the inner edge of the walk-way and adapted to be lowered into and elevated from the cover internal openings.

Abstract: The invention is concerned with training fish, such as salmonoids and other varieties exhibiting similar growth habits and characteristics, to live and feed in concentrated vertical stacks under light-blocking covers contacting the water (floating upon or submerged, partly or totally), such that the fish need not be contained by nets, walls or other barriers in the sea or other water bodies; and then may be harvested or otherwise collected or even transported, when desired, by enclosing or sweeping the dark areas under the covers by nets or cages or the like, or transporting the covers, with the fish moving to stay in the dark areas thereunder, to an enclosed, netted or otherwise barriered area.

Abstract: This disclosure is concerned with the more efficient utilization of fish feed, such as the pelletized feed for salmonoids and the like, introduced into pluralities of ponds, through appropriate bottom funneling of uneaten feed and waste water and utilization of the exiting waste water to carry the uneaten feed for injection into a next pool after separation from the carrying waste water; the process being applicable to any type of pond, but particularly suitable for ponds in which dark rest areas are provided for accelerated growth.

Abstract: This disclosure is concerned with accelerating the growth rate of dense populations of salmonoids and other fish of related characteristics in ponds and the like by providing a light-blocked cover-shielded area over a substantial portion of the pond under which the fish can rest in darkness, with surrounding illuminated areas for visual feeding, and preferably with extended periods of illumination during continued feeding up to 24 hours, continuously.