Explanation: Species within the *Salmo* genus are native to the North Atlantic basin, whereas species belonging to the *Oncorhynchus* genus are predominantly found in the North Pacific basin.

Explanation: The Atlantic salmon, *Salmo salar*, belongs to the genus *Salmo*, not *Oncorhynchus*. It is native to both sides of the North Atlantic Ocean.

Explanation: The *Oncorhynchus* genus contains 12 recognized species, primarily known as Pacific salmon, but they are native only to the North Pacific basin, not found globally.

Explanation: Both Chinook salmon (*Oncorhynchus tshawytscha*) and Atlantic salmon (*Salmo salar*) share a maximum recorded length of approximately 150 cm, but Chinook salmon can attain a greater maximum weight (up to 61.4 kg) compared to Atlantic salmon (up to 46.8 kg).

Explanation: Pink salmon (*Oncorhynchus gorbuscha*) typically have the shortest maximum lifespan among common salmon species, generally living up to 3 years.

Explanation: The Masu salmon is scientifically known as *Oncorhynchus masou* and is found in the western Pacific Ocean. The genus *Salmo* is primarily associated with Atlantic salmon and related species.

Explanation: The Australian salmon (*Arripis trutta*) belongs to the order Perciformes, not Salmoniformes. Therefore, it is not considered a true salmon, despite its common name.

Explanation: The two principal genera are *Salmo*, native to the North Atlantic basin, and *Oncorhynchus*, native to the North Pacific basin.

Explanation: While trout, char, and grayling are closely related coldwater fish often found in similar regions as salmon, pike are generally considered distinct and are not typically listed among the closest relatives in this context.

Explanation: The 12 recognized species within the *Oncorhynchus* genus are naturally found exclusively in the North Pacific basin.

Explanation: Pink salmon (*Oncorhynchus gorbuscha*) typically have the shortest maximum lifespan among common salmon species, generally living up to 3 years.

Explanation: The Australian salmon (*Arripis trutta*) is scientifically classified within the order Perciformes, distinguishing it from true salmon, which belong to the order Salmoniformes.

Explanation: Anadromous behavior describes a life cycle where salmon hatch in freshwater, migrate to the ocean to mature, and subsequently return to their freshwater birthplace to reproduce.

Explanation: Scientific evidence suggests that salmon primarily utilize olfactory memory, detecting familiar chemical cues in the water, to navigate back to their natal streams for spawning, rather than relying solely on visual cues.

Explanation: A 'grilse' is specifically an Atlantic salmon that returns to spawn after only one year of feeding in the sea; fish spending multiple years at sea are typically larger.

Explanation: Prior to spawning, salmon undergo significant physical transformations, including changes in coloration (often becoming darker or more vibrant) and the development of pronounced features like a hooked jaw ('kype') in males, rather than becoming more silvery with smoother skin.

Explanation: Semelparity is precisely defined as a reproductive strategy characterized by reproducing only once in an organism's lifetime, followed by death, a trait common among Pacific salmon species.

Explanation: A female salmon constructs a redd by using her tail to excavate a depression in the gravel riverbed, not with her mouth. This action allows the current to sweep gravel downstream, forming the nest.

Explanation: Salmon fry initially feed on zooplankton. As they develop into juveniles (parrs), their diet shifts to include aquatic invertebrates, insects, and small baitfish.

Explanation: Anadromous behavior signifies a life cycle that begins in freshwater, transitions to the ocean for growth and maturation, and culminates in a return migration to freshwater for reproduction.

Explanation: Scientific consensus indicates that salmon primarily employ olfactory memory, enabling them to detect and follow specific chemical signatures in the water to locate their natal streams.

Explanation: A redd is the nest constructed by a female salmon in the gravel riverbed, specifically designed to protect her eggs during incubation.

Explanation: Semelparity describes the reproductive strategy of organisms that reproduce only a single time during their lives, typically dying shortly thereafter, which is characteristic of Pacific salmon.

Explanation: Prior to spawning, salmon undergo significant morphological changes, including altered coloration and, in males, the development of a pronounced hooked jaw known as a 'kype'.

Explanation: In Atlantic salmon populations, a 'grilse' refers to an individual that returns to freshwater to spawn after spending only one year feeding in the marine environment.

Explanation: While salmon are part of the food web, their designation as keystone species in the Pacific Northwest stems primarily from their role in facilitating a massive transfer of marine nutrients to inland freshwater and terrestrial ecosystems.

Explanation: Bears play a crucial role in nutrient cycling by transporting salmon from aquatic environments to terrestrial areas, where their waste and uneaten portions fertilize the riparian zone.

Explanation: Beaver dams can positively influence juvenile salmon habitat by creating ponds that offer slow-water environments and structural complexity, aiding in predator avoidance and retaining nutrients.

Explanation: Anadromous lampreys contribute positively to salmon ecosystems by releasing nutrients after spawning and serving as a food source for young salmon. Their larvae also improve water quality.

Explanation: After spawning, salmon carcasses decompose in freshwater streams, releasing vital nutrients into these aquatic environments, thereby supporting freshwater and riparian ecosystems, rather than primarily serving marine predators in the ocean.

Explanation: Salmon are considered keystone species due to their critical role in transporting substantial quantities of marine-derived nutrients (nitrogen, phosphorus, etc.) from the ocean to inland freshwater and terrestrial ecosystems.

Explanation: Bears facilitate nutrient transfer by consuming salmon and depositing nutrient-rich waste and uneaten carcasses onto terrestrial areas adjacent to waterways, thereby fertilizing riparian ecosystems.

Explanation: Beaver dams create ponds that offer juvenile salmon refuge by providing slow-water habitats and complex structures that help them avoid predators.

Explanation: Anadromous lampreys contribute positively by releasing nutrients upon death post-spawning and by their larvae improving water quality through filter-feeding, while also serving as a food source for juvenile salmon.

Explanation: While Atlantic salmon (*Salmo salar*) is listed as 'Near threatened' by the IUCN, Chum salmon (*Oncorhynchus keta*) is classified as 'Least concern'.

Explanation: The Danube salmon (*Hucho hucho*), or huchen, is indeed listed as 'Endangered' on the IUCN Red List, reflecting significant threats to its populations.

Explanation: *Henneguya salminicola* is a parasite that forms cysts in salmon flesh, but it is generally considered non-pathogenic, meaning it does not typically cause disease or impede the fish's ability to spawn.

Explanation: Sea lice infestations, particularly when amplified by the presence of salmon farms, can pose a significant threat, leading to high mortality rates in young wild salmon migrating to sea.

Explanation: The 1914 slide at Hells Gate had a severe detrimental impact on the Fraser River salmon population, leading to a substantial reduction in catches in subsequent years.

Explanation: Current Pacific salmon populations are estimated to be only 1-3% of their historical levels at the time of the Lewis and Clark expedition, indicating a drastic decline.

Explanation: The Chief Joseph Dam completely blocks salmon migration to the historical spawning grounds in the upper Columbia River system.

Explanation: Concerns regarding wild salmon populations extend to both the North Pacific and North Atlantic basins. Declines have been noted in North Atlantic populations, as well as in various North American Pacific systems.

Explanation: Research indicates that the size of several Pacific salmon species has actually decreased over the past 30 years, potentially due to factors such as climate change and increased competition from other salmon populations.

Explanation: The M74 syndrome is a condition linked to thiamine (vitamin B1) deficiency, which critically impairs egg viability and leads to high mortality rates in newly hatched salmon fry.

Explanation: The decline in wild salmon populations is indeed multifactorial, with habitat degradation, unsustainable fishing practices, and broader environmental shifts identified as primary contributing causes.

Explanation: The International Union for Conservation of Nature (IUCN) lists the Atlantic salmon (*Salmo salar*) as 'Near Threatened'.

Explanation: Elevated levels of sea lice, often associated with aquaculture operations, can cause severe and frequently lethal infestations in juvenile wild salmon as they migrate from freshwater to the ocean.

Explanation: The 1914 Hells Gate slide drastically reduced the Fraser River salmon catch, with the 1917 catch being only a quarter of that recorded in 1913, illustrating the severe impact.

Explanation: *Henneguya salminicola* forms cysts within salmon flesh but typically does not induce significant disease or impede the fish's reproductive capabilities.

Explanation: The M74 syndrome is associated with deficiencies in thiamine (vitamin B1), which critically impacts the viability of salmon eggs and the survival of newly hatched fry.

Explanation: The decline in wild salmon populations is primarily attributed to a confluence of factors including habitat destruction, unsustainable fishing pressures, and broader environmental shifts.

Explanation: Salmon hold significant economic importance globally through commercial fishing and aquaculture, and they are also highly prized by recreational anglers.

Explanation: Various salmon species have been successfully established in introduced environments, including the Great Lakes region of North America, Patagonia in South America, and New Zealand's South Island.

Explanation: Theodore Roosevelt's 1908 address highlighted the significant decline of salmon fisheries on the Columbia River, attributing it to ineffective management and inter-state disagreements, not thriving conditions.

Explanation: The market availability differs significantly: nearly all Atlantic salmon are farmed, whereas the majority of Pacific salmon are wild-caught.

Explanation: Ocean ranching is a method where young salmon are released into the ocean to mature, with the expectation that they will return to designated points for harvest, rather than being raised in enclosed pens.

Explanation: Spawning channels are constructed to provide a stable environment for egg incubation by controlling water flow and removing sediment, thereby preventing floods from washing out nests and ensuring suitable conditions for development, not primarily to facilitate adult migration speed.

Explanation: While salmon have been established in the Great Lakes, they are not self-sustaining and require continuous stocking; they support a sport fishery but not a large commercial one.

Explanation: Salmon farming requires substantial quantities of feed derived from wild forage fish, placing significant pressure on these populations and potentially impacting other marine species that rely on them.

Explanation: The Great Lakes, Patagonia, and the South Island of New Zealand are cited as locations where salmon have been successfully introduced. The Mediterranean Sea is not mentioned in this context.

Explanation: President Roosevelt observed in 1908 that salmon fisheries on the Columbia River had declined substantially, attributing this to a lack of effective management and disputes between states, which prevented adequate numbers from reaching spawning grounds.

Explanation: The global market for salmon shows a distinct difference: Atlantic salmon is predominantly farmed (nearly 99%), whereas Pacific salmon species are predominantly wild-caught (over 80%).

Explanation: Artificial spawning channels are engineered to offer a controlled and stable environment for salmon eggs, mitigating risks associated with natural floods and sediment deposition that can compromise egg survival.

Explanation: The substantial requirement for feed in salmon aquaculture places considerable pressure on wild forage fish populations, potentially leading to overexploitation and ecosystem imbalances.

Explanation: The English word 'salmon' derives from Latin ('salmo'), which is speculated to originate from 'salire', meaning 'to leap', rather than from a Greek word.

Explanation: Salmon are profoundly culturally and spiritually significant for Indigenous peoples of the Pacific Northwest, forming a cornerstone of their traditions, subsistence, and ecological worldview.

Explanation: The word 'salmon' is linked to the Latin word 'salire', which means 'to leap', likely referring to the fish's upstream migratory behavior, not 'to swim slowly'.

Explanation: Indigenous fishing practices, such as the 'first salmon ceremony', exemplify profound ecological understanding and deep respect for salmon, reflecting sustainable harvesting traditions and spiritual connections.

Explanation: Across various cultures, salmon are predominantly depicted in mythology as symbols of wisdom, knowledge, abundance, and spiritual significance, rather than greed or destruction.

Explanation: The 'salmon argument' refers to a linguistic debate concerning the origin of Indo-European languages, where the etymology of the word 'salmon' was historically considered significant, not fishing techniques.

Explanation: The Latin word 'salire', from which 'salmo' (and thus 'salmon') is thought to derive, means 'to leap', likely referencing the salmon's characteristic behavior of leaping upstream during its spawning migration.

Explanation: Salmon hold profound cultural and spiritual importance for Indigenous peoples of the Pacific Northwest, serving as a fundamental food source and deeply influencing their traditions, ceremonies, and ecological practices.

Explanation: Salmon is classified as an oily fish, rich in protein, omega-3 fatty acids, and vitamin D, not a lean fish low in these beneficial components.

Explanation: Astaxanthin is a pigment responsible for the characteristic pink-to-red color of salmon flesh, not white. It is obtained naturally by wild salmon and often supplemented in the feed of farmed salmon to achieve this color.

Explanation: While some studies indicate higher contaminant levels in farmed salmon, research generally concludes that the substantial nutritional benefits of consuming salmon, even farmed varieties, outweigh potential risks.

Explanation: In British Columbia, the term 'tyee' specifically designates a Chinook salmon weighing over 30 pounds, signifying a particularly large specimen.

Explanation: The distinction lies in the temperature: hot-smoking involves cooking at higher temperatures, while cold-smoking cures the fish at lower temperatures, resulting in different textures and preservation qualities.

Explanation: Salmon is recognized for its nutritional value, being an excellent source of high-quality protein, beneficial omega-3 fatty acids, and vitamin D, classifying it as an oily fish.

Explanation: In British Columbia, the term 'tyee' is specifically used to denote a Chinook salmon that exceeds 30 pounds in weight.