Although ultrasound is currently used in the Columbia basin (e.g., for steelhead smolts by the Yakama Nation), aspects of the techniques proposed are innovative. However, the proposal is not convincing that the work will be sufficiently valuable to restoration of salmon or sturgeon. The proposed budget is excessively devoted to equipment purchases. The investigators' roles are not clearly defined and they do not present evidence (publications) of their qualifying experience.
There are concerns about the proposers' justification for the research. They suggest that the high proportion of salmon males in hatchery populations is a barrier to restoration, referring to the danger and burden of 'extra males'. However, the objective of a supplementation hatchery is to maintain effective breeding number as high as possible, to maximize variance/inbreeding effective population size, which means never excluding a member of the population, male or female, from breeding. Artificial manipulation of sex ratios might have profound deleterious effects on fitness of wild populations in communication with hatchery populations. The proposers assume away these issues without considering them; they cite a paper by Fleming dated 1993, but do not give the full citation so it's hard to know what justification they may be guided by. They also suggest that reducing the number of males in supplemental hatchery releases would ameliorate density dependent ecological effects on wild salmon. There would be no need to screen sexes to ameliorate that effect as amelioration can be accomplished simply by reducing the number of smolts released. Preferring females in smolts at release would exacerbate one form of density dependent interaction, that of competition in space and time among females for redd sites—the most well known form of density dependent interactions in Pacific salmon.
There are also concerns about the likely success of the proposed technique. The proposers' suggestion that ultrasound imaging could distinguish testes from ovaries in immature smolts is not convincingly argued. Perhaps the maturing testes of jacks of some species would be distinguishable. The proposers do not describe their own dissections of smolts and do not give us a basis for comparison of sizes of testes and ovaries for judging their proposal that ultrasound techniques would be able to distinguish the two structures. They suggest that the technique can 'image' the heart valve of a mouse but don't tell us whether that valve is smaller than the diameter of a smolt's gonad.