WDFW Forage Fish Information

Sand Lance - Biology

Name: Pacific sand lance, Ammodytes hexapterus Photo; tub o' sand lance

Geographical range: The Pacific sand lance occurs throughout the coastal northern Pacific Ocean from the Sea of Japan to southern California and across Arctic Canada.

Related species: Sand lance fish are occasionally referred to as "candlefish", however, on the Pacific Coast "candlefish" correctly refers to the eulachon (Columbia River smelt), an unrelated species. Several closely related species occur on both shores of the north Atlantic Ocean, Greenland and the European Arctics, where they are commonly called "sand eels". While no closely related species are found in Washington, other forage fish include herring, surf smelt and anchovy.

Local Distribution: Sand lance populations are widespread within Puget Sound, the Strait of Juan de Fuca and the coastal estuaries of Washington. They are most commonly noted in more localized areas, such as the eastern Strait and Admiralty Inlet. However, WDFW plankton surveys and ongoing exploratory spawning habitat surveys suggest that there are very few if any bays and inlets in the Puget Sound basin that will not be found to support sand lance spawning activity.

Life History:The sand lance is a common but poorly known near shore schooling fish in Washington waters. The abundance and broad distribution of planktonic sand lance larvae throughout the bays and inlets of Puget Sound in late winter suggested that their spawning habitats and spawning activity are widespread in the region. Since 1991, WDFWs Forage Fish Unit has undertaken a systematic intertidal beach substrate sampling strategy along a significant proportion of the shoreline of the Puget Sound basin. Sand lance were first found to have deposited spawn in the upper intertidal zone in 1989 by WDFW investigators. Evidence of sand lance spawning activity has now been documented at numerous locations totaling about 130 miles of Puget Sound shoreline, and many potential sand lance spawning areas remain to be surveyed.

Photo: sand lance eggs covered with sand

Sand lance deposit eggs on a rather broad range of beach surface substrates, from soft, pure fine sand beaches to beaches armored with gravel up to 3 cm in diameter, although most spawning appears to occur on the finer grained substrates. Sand lance eggs acquire a partial coat of sand grains which adhere during deposition. The sand coating may serve to assist in capillary moisture retention when the eggs are exposed during the low tide. The coated sand lance eggs are dispersed along the beach with each tide exchange.

Fresh, intact sand lance spawn deposits commonly consist of small (less than 10 cm in diameter) patches of eggs, either resting in the bottom of shallow pits in the beach or scattered irregularly over a broad zone of disrupted beach surface. Such features suggest a certain degree of vigor in the sand lance mass spawning act.

Spawning occurs at tidal elevations ranging from +5 feet to about the mean higher high water line. After deposition, sand lance eggs may be scattered over a wider range of the intertidal zone by wave action. The incubation period is about four weeks.

Upon hatching, the larval sand lance measures about 5 mm, and are virtually transparent. Like other forage fish, larvae and juvenile sand lance are subject to predation. As larvae they are at the mercy of the local currents and tides until they are about 22 mm in length. They then "school up", adopt their adult coloration and can be found in bays and inlets throughout Puget Sound.

Line drawing of a sand lance postlarvae.

Sand lance are somewhat unique in their generalized diurnal behavior pattern, feeding in the open water during the day and burrowing into the sand at night to avoid predation. Sand lance do not appear to be amenable to the acoustic or spawn survey techniques currently used by WDFW for herring and surf smelt stock assessment.

The movements and age structure of adult sand lance populations are currently unknown. Sand lance are most frequently observed when "balling", a behavior also demonstrated by Pacific herring. When schooling sand lance are attacked, usually by diving birds, the individuals begin swimming in a compressed circular pattern, forming a tight swirling ball. This behavior is thought to be adaptive for individual survival. By compressing the school and circling, the chance of any individual herring being eaten is reduced as compared to that of an individual herring traveling in a normal schooling pattern. Once the sand lance have "balled", other predators may join in the attack including seals, sea lions, dogfish, gulls and humans.

Sand Lance - Management

Investigations of sand lance have been conducted in the Puget Sound basin since 1989. The activities have been primarily directed to spawning habitat documentation. Although populations of the Pacific sand lance are known to occur throughout the waters of the outer coast of Washington, no comprehensive biological studies or spawning habitat surveys of outer coast sand lance stocks have been undertaken. Catches and seasons are regulated with time/area/gear restrictions through the Washington Administrative Code.

Spawning; timing and grounds

Chart of documented sand lance spawning grounds.

Sand lance spawning activity appears to be distributed throughout the shorelines of the Puget Sound basin. The adjacent chart shows currently documented sand lance spawning grounds in yellow. (Documented sand lance spawning grounds GIF , 19k.) Sand lance spawning activity takes place annually from November 1 through approximately February 15. There do not appear to be regional differences in sand lance spawning seasons.

Sand Lance - Habitat

The sand lance's habit of spawning in the upper intertidal zone of sand gravel beaches throughout the increasingly populated Puget Sound basin makes it vulnerable to the cumulative effects of various types of shoreline development. The Washington Administrative Code Hydraulic Code Rules for the control and permitting of in-water construction activities in Washington now include consideration of sand lance spawning habitat protection as resource agency staff review shoreline project designs and formulate responses to Hydraulic Permit Applications.

Sand Lance - Fisheries

Sand lance are not regularly harvested for bait or human consumption in Washington. When harvested the species is commonly dip netted for salmon sport bait. For the period 1975 to 1994, only one legal landing of sand lance was reported. In July 1993, a commercial sport bait boat dipped an 80 pound ball of young of the year sand lance (10,800 estimated fish) near Olympia, and sold them as bait. The sport harvest has not be estimated.

Sand Lance - Ecosystem Context

Sand lances are an important part of the trophic link between zoolplankton and larger predators in the local marine food webs. Like all forage fish, sand lance are a significant component in the diet of many economically important resources in Washington. On average, 35 percent of juvenile salmon diets are comprised of sand lance. Sand lance are particularly important to juvenile Chinook, where 60 percent of their diets are sand lance. Other economically important species, such as Pacific cod (Gadus macrocephalus), Pacific hake (Merluccius productus) and dogfish (Squalus acanthias) feed heavily on juvenile and adult sand lance.


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