Seagrass wasting disease, caused by parasitic slime nets in the genus Labyrinthula , affects seagrasses globally with outbreaks occurring at local to regional scales. Though prior research showed variation in pathogenicity across strains, little is known about the broad-scale diversity and biogeography of Labyrinthula species. We used targeted amplicon-based high throughput sequencing (HTS) to examine the phylogeography of Lab...

The offshore Gulf of Alaska—in the northeastern subarctic Pacific—is a high-nitrate, low-chlorophyll (HNLC) oceanic region where concentrations of dissolved iron (DFe) and zinc (DZn) are of the order ~0.1 nmol kg −1 in surface waters. At the average winter mixed layer depth of ~120 m, DFe and DZn are of the orders ~0.1–0.2 nmol kg −1 and ~1–2 nmol kg −1 , respectively. Vertical supply of Fe to surface waters is therefore limit...

Continental margins are disproportionally important for global primary production, fisheries and CO 2 uptake. However, across the Northeast Atlantic shelves, there has been an ongoing summertime decline of key biota—large diatoms, dinoflagellates and copepods—that traditionally fuel higher tropic levels such as fish, sea birds and marine mammals. Here, we combine multiple time series with in situ process studies to link these...

Primary production in the Ross Sea, one of the most productive areas in the Southern Ocean, has previously been shown to be seasonally limited by iron. In two of three bottle incubation experiments conducted in the austral summer, significantly higher chlorophyll a (Chl a ) concentrations were measured upon the addition of iron and B 12 , relative to iron additions alone. Initial bacterial abundances were significantly lower i...

Near‐surface seawater from the northeastern subarctic Pacific was incubated on deck for 8 d, supplemented with (1) control, no additions (2) +Zn (3) +Fe (4) +Zn+Fe. Concentrations of total Zn and Fe at time zero (t 0 ) and in the control remained at ~0.1–0.2 nmol L −1 . In the control, chlorophyll (=0.3 mg m −3 ), 14 C uptake into POC and PIC, and inorganic nutrients all remained relatively constant. Addition of Zn slightly bu...