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Primary production in the sunlit surface ocean is regulated by the supply of key nutrients, primarily nitrate, phosphate and iron (Fe), required by phytoplankton to fix carbon dioxide into biomass1–3. Below the surface ocean, remineralization of sinking organic matter rapidly regenerates nutrients, and microbial metabolism in the upper mesopelagic ‘twilight zone’ (200–500 m) is thought to be limited by the delivery of labile organic carbon4,5. However, few studies have examined the role of nutrients in shaping microbial production in the mesopelagic6–8. Here we report the distribution and uptake of siderophores, biomarkers for microbial Fe deficiency9across a meridional section of the eastern Pacific Ocean. Siderophore concentrations are high not only in chronically Fe-limited surface waters but also in the twilight zone underlying the North and South Pacific subtropical gyres, two key ecosystems for the marine carbon cycle. Our findings suggest that bacterial Fe deficiency owing to low Fe availability is probably characteristic of the twilight zone in several large ocean basins, greatly expanding the region of the marine water column in which nutrients limit microbial metabolism, with potential implications for ocean carbon storage.

She best at what they do... Few can make such a claim, but those who reach that pinnacle set a standard toward which all can strive, and the industry is [...]

Cold, rainy days can quickly transform outdoor water parks into ghost towns. But operators of indoor water parks can weather a freezing December morning as easily as a scorching summer [...]

With all due respect to the person who penned the phrase, 'You can't please all the people, all the time,' town officials in Huntersville, N.C., have something to say: 'Wrong!' [...]

Suggestions are presented for maintaining lazy rivers which require proper safety and maintenance procedures for the prevalent landscaping. Large numbers of guests and relatively shallow water create the need for diligence and imagination in maintenance and safety challenges.

Adjustable swimming pool floors are desirable for the flexibility they provide, especially when space is limited. Floors can be adjusted for the different depths needed for adult and child swimmers, and raised to floor level to provide additional meeting space. The costs and considerations of installing an adjustable floor are detailed.

Wave pools, which generate simulated swells of nearly 10 feet, are major attractions at water parks. Equipment failure disappoints patrons and causes spill-over to other attractions, complicating the frustration. Tips for maintaining wave pools are provided.

Issues concerning safely handling large crowds at leisure pool facilities, while maintaining the customer's satisfaction, are presented. Attendance at these facilities may sometimes be more than 10 times the number of visitors at traditional pools.

The state-of-the-art natatorium and other sports facilities at the new Rosewood Community Center in Commerce, CA, are described. The aquatics center includes a 36-meter competitive pool, a 25-meter warm-up pool and a wading pool.

The programs at seven award-winning aquatic facilities are described. The winners include the Harbor Athletic Club in Middleton, WI, the Courage Center in Minneapolis, MN, and the University of Minnesota.

On site waterparks are being built by resorts and hotels, thereby increasing significantly their room rates and occupancy levels. Both existing and new hotels equally are adding these water slides, wave pools and lazy rivers to remain competitive.

Issues are described concerning the next revolution in the aquatics industry, interactive features at waterparks. Timed racing slides, automated dumping and water guns increase attendance by reducing long lines with dynamic, high-capacity rides.

Stainless steel and other alternatives to standard rectangular pools are being offered with more options, quicker installation and easier maintenance. Concrete remains the dominate choice, while fiberglass, vinyl, PVC and stainless steel are becoming competitive in the commercial market.

Wisconsin Dell visitors may choose from 11 indoor waterparks year-round.

Nickel is a biologically essential element for marine life, with the potential to influence diverse processes, including methanogenesis, nitrogen uptake and coral health, in both modern and past oceans. However, an incomplete view of oceanic Ni cycling has stymied understanding of how Ni may impact marine life in these modern and ancient oceans. Here we combine data-constrained global biogeochemical circulation modelling with culture experiments and find that Ni in oligotrophic gyres is both chemically and biologically labile and only minimally incorporated into diatom frustules. We then develop a framework for understanding oceanic Ni distributions, and in particular the two dominant features of the global marine Ni distribution: the deep concentration maximum and the residual pool of approximately 2 nM Ni in subtropical gyres. We suggest that slow depletion of Ni relative to macronutrients in upwelling regions can explain the residual Ni pool, and reversible scavenging or slower regeneration of Ni compared with macronutrients contributes to the distinct Ni vertical distribution. The strength of these controls may have varied in the past ocean, impacting Ni bioavailability and setting a fine balance between Ni feast and famine for phytoplankton, with implications for both ocean chemistry and climate state.

Many cities are building versatile leisure pools to help recover operating expenses and to serve a more diverse population. Fifty-meter pools are first choice for competition events but drain funds of most cities.

Marine dissolved organic matter (DOM) contains a complex mixture of small molecules that eludes rapid biological degradation. Spatial and temporal variations in the abundance of DOM reflect the existence of fractions that are removed from the ocean over different time scales, ranging from seconds to millennia. However, it remains unknown whether the intrinsic chemical properties of these organic components relate to their persistence. Here, we elucidate and compare the molecular compositions of distinct DOM fractions with different lability along a water column in the North Atlantic Gyre. Our analysis utilized ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry at 21 T coupled to liquid chromatography and a novel data pipeline developed in CoreMS that generates molecular formula assignments and metrics of isomeric complexity. Clustering analysis binned 14 857 distinct molecular components into groups that correspond to the depth distribution of semilabile, semirefractory, and refractory fractions of DOM. The more labile fractions were concentrated near the ocean surface and contained more aliphatic, hydrophobic, and reduced molecules than the refractory fraction, which occurred uniformly throughout the water column. These findings suggest that processes that selectively remove hydrophobic compounds, such as aggregation and particle sorption, contribute to variable removal rates of marine DOM.

Much flak has been directed at BT and telecoms regulator Oftel. Tim Conway looks at the troubled history of communications regulation in the UK and suggests a new way forward […]

The measurable supply of 232Th to the ocean can be used to derive the supply of other elements, which is more difficult to quantify directly. The measured inventory of an element divided by the derived supply yields a replacement time estimate, which in special circumstances is related to a residence time. As a proof of concept, Th‐based supply rates imply a range in the replacement times of the rare earth elements in the North Atlantic that is consistent with the chemical reactivity of rare earth elements related to their ionic charge density. Similar estimates of replacement times for the bioactive trace elements (Fe, Mn, Zn, Cd, Cu, and Co), ranging from <5 years to >50,000 years, demonstrate the broad range of elemental reactivity in the ocean. Here we discuss how variations in source composition, fractional solubility ratios, or noncontinental sources, such as hydrothermal vents, lead to uncertainties in Th‐based replacement time estimates. We show that the constraints on oceanic replacement time provided by the Th‐based calculations are broadly applicable in predicting how elements are distributed in the ocean and for some elements, such as Fe, may inform us on how the carbon cycle may be impacted by trace element supply and removal. Thorium‐232 supply rates produce reasonable ocean replacement times for the rare earth elementsIron residence time in the North Atlantic may be less than 6 yearsThorium‐232 supply rates may provide an accurate basis for the supply of many other elements for constraining biogeochemical models

Substantial amounts of nitrogen fixation occur in the North Atlantic subtropical gyre, due to the activity of cyanobacteria with high iron requirements. Iron is delivered to this region by dust from the Sahara Desert. However, this dust deposition is typically localized and episodic. Therefore, other sources of iron may also be important. Here, we report observations of dissolved iron concentrations in a Gulf Stream cold-core ring, which transported iron-rich water from near the continental slope into the subtropical gyre. We find that iron concentrations were elevated in the ring compared with subtropical waters, reflecting its source waters. Using iron data from these source waters and the identification of ring activity in satellite data, we estimate that cold-core rings provide a net flux of 0.3 ± 0.17 × 108mol Fe yr−1across the northwestern gyre edge, on the order of 15% of our median estimates of gyre-wide supply of iron by dust deposition. We suggest that iron supply from cold-core rings is an important source of iron to the northwestern gyre edge. We conclude that mesoscale ocean circulation features may play an important role in subtropical nutrient and carbon cycling. Gulf Stream rings may carry substantial amounts of iron to the North Atlantic subtropical gyre, according to measurements of iron concentrations in a ring and satellite data on ring activity.

No longer is the elegant look of stone coping reserved strictly for gunite pools. Now innovations for attaching stone coping can make it difficult to distinguish package pools from gunite [...]

Pacific Pools and Performance Products, a leading manufacturer of polymer inground pool kits, once again is under the stewardship of the Laven family, the company's original owners. Mark Laven, son [...]

Booth location seemed to be the deciding factor between a hot trade show and a lukewarm event for exhibitors at the 2001 International Pool & Spa Expo, held Nov. 26-30 [...]

Shoppers will likely cut back on spending this holiday season, but perhaps not as drastically as many retailers and economists fear, according to two recent surveys. A survey conducted jointly [...]

A late surge in exhibitor sign-ups for next weeks 2001 International Pool & Spa Expo in Phoenix has pushed the total number of exhibitors to 543, up from 465 in [...]

California Assembly Bill 663 could increase protection for lifeguards injured on the job. It would provide the same workers' compensation benefits for lifeguards as already being provided firefighters and police officers. Illnesses arising out of employment such as cancer, leukemia, pneumonia and tuberculosis would be covered.

A National Aquatics Management School workshop at the 16th National Recreation and Park Association's Aquatic conference discussed issues of pressing concern to the industry. Foremost on the minds of industry professionals are lifeguard recruiting problems and financial difficulties.

Issues and presented concerning conservation of electricity by aquatic facilities prompted by California's ongoing power crisis.

The success of US aquatic athletes in the 2000 Olympics should provide a strong boost to participation in school and club aquatic programs. The timing of the Sydney Olympics may delay the effect.

An analysis of the revised CPR guidelines of the American Heart Association is presented. One recommended change is that the same compression-to-breath ratio be used in both single- and two-person CPR.

Vacancies for lifeguards are increasingly difficult to fill due to increased responsibilities and low wages and benefits.

Despite the Pacific being the location of the earliest seawater Cd studies, the processes which control Cd distributions in this region remain incompletely understood, largely due to the sparsity of data. Here, we present dissolved Cd and δ114Cd data from the US GEOTRACES GP15 meridional transect along 152°W from the Alaskan margin to the equatorial Pacific. Our examination of this region's surface ocean Cd isotope systematics is consistent with previous observations, showing a stark disparity between northern Cd‐rich high‐nutrient low‐chlorophyll waters and Cd‐depleted waters of the subtropical and equatorial Pacific. Away from the margin, an open system model ably describes data in Cd‐depleted surface waters, but atmospheric inputs of isotopically light Cd likely play an important role in setting surface Cd isotope ratios (δ114Cd) at the lowest Cd concentrations. Below the surface, Southern Ocean processes and water mass mixing are the dominant control on Pacific Cd and δ114Cd distributions. Cd‐depleted Antarctic Intermediate Water has a far‐reaching effect on North Pacific intermediate waters as far as 47°N, contrasting with northern‐sourced Cd signatures in North Pacific Intermediate Water. Finally, we show that the previously identified negative Cd* signal at depth in the North Pacific is associated with the PO4maximum and is thus a consequence of an integrated regeneration signal of Cd and PO4at a slightly lower Cd:P ratio than the deep ocean ratio (0.35 mmol mol−1), rather than being related to in situ removal processes in low‐oxygen waters. Atmospheric inputs of isotopically light Cd play an important role in setting surface δ114Cd when surface Cd concentrations are lowStrong Southern Ocean control on subsurface Cd and δ114Cd distribution; Antarctic Intermediate Water influences δ114Cd of North Pacific intermediate watersA Cd* minimum at depth in the North Pacific is associated with the PO4maximum, a consequence of integrated regeneration Atmospheric inputs of isotopically light Cd play an important role in setting surface δ114Cd when surface Cd concentrations are low Strong Southern Ocean control on subsurface Cd and δ114Cd distribution; Antarctic Intermediate Water influences δ114Cd of North Pacific intermediate waters A Cd* minimum at depth in the North Pacific is associated with the PO4maximum, a consequence of integrated regeneration

The Southeast Pacific Ocean is a severely understudied yet dynamic region for trace metals such as iron, since it experiences steep redox and productivity gradients in upper waters and strong hydrothermal iron inputs to deep waters. In this study, we report the dissolved iron (dFe) distribution from seven stations and Fe isotope ratios (d56Fe) from three of these stations across a near-zonal transect from 20 to 27°S. We found elevated dFe concentrations associated with the oxygen-deficient zone (ODZ), with light d56Fe implicating porewater fluxes of reduced Fe. However, temporal dFe variability and rapid d56Fe shifts with depth suggest gradients in ODZ Fe source and/or redox processes vary over short-depth/spatial scales. The dFe concentrations decreased rapidly offshore, and in the upper ocean dFe was controlled by biological processes, resulting in an Fe:C ratio of 4.2?µmol/mol. Calculated vertical diffusive Fe fluxes were greater than published dust inputs to surface waters, but both were orders of magnitude lower than horizontal diffusive fluxes, which dominate dFe delivery to the gyre. The d56Fe data in the deep sea showed evidence for a -0.2‰ Antarctic Intermediate Water end-member and a heavy d56Fe of +0.55‰ for distally transported hydrothermal dissolved Fe from the East Pacific Rise. These heavy d56Fe values were contrasted with the near-crustal d56Fe recorded in the hydrothermal plume reaching Station ALOHA in the North Pacific. The heavy hydrothermal d56Fe precludes a nanopyrite composition of hydrothermal dFe and instead suggests the presence of oxides or, more likely, binding of hydrothermal dFe by organic ligands in the distal plume. Elevated dFe in the Chilean ODZ is derived from porewater but is redox cycled on short spatiotemporal scalesVanishingly low dFe in the surface gyre is dominated by horizontal fluxes and less by dust inputsHydrothermal-derived deep dFe is isotopically heavy in the South Pacific, while it has near-crustal isotope composition at Station ALOHA

Glacier meltwater supplies silicon (Si) and iron (Fe) sourced from weathered bedrock to downstream ecosystems. However, the extent to which these nutrients reach the ocean is regulated by the nature of the benthic cycling of dissolved Si and Fe within fjord systems, given the rapid deposition of reactive particulate fractions at fjord heads. Here, we examine the benthic cycling of the two nutrients at four Patagonian fjord heads through geochemical analyses of sediment pore waters, including Si and Fe isotopes (δ30Si and δ56Fe), and reaction‐transport modeling for Si. A high diffusive flux of dissolved Fe from the fjord sediments (up to 0.02 mmol m−2day−1) compared to open ocean sediments (typically <0.001 mmol m−2day−1) is supported by both reductive and non‐reductive dissolution of glacially‐sourced reactive Fe phases, as reflected by the range of pore water δ56Fe (−2.7 to +0.8‰). In contrast, the diffusive flux of dissolved Si from the fjord sediments (0.02–0.05 mmol m−2day−1) is relatively low (typical ocean values are >0.1 mmol m−2day−1). High pore water δ30Si (up to +3.3‰) observed near the Fe(II)‐Fe(III) redox boundary is likely associated with the removal of dissolved Si by Fe(III) mineral phases, which, together with high sedimentation rates, contribute to the low diffusive flux of Si at the sampled sites. Our results suggest that early diagenesis promotes the release of dissolved Fe, yet suppresses the release of dissolved Si at glaciated fjord heads, which has significant implications for understanding the downstream transport of these nutrients along fjord systems. Through physical grinding and chemical reactions, glaciers are capable of releasing nutrients such as silicon and iron from the underlying rocks. In particular, there is a growing interest in the supply of these glacier‐sourced nutrients to sustain the growth of marine life in high‐latitude estuaries (fjords) and the adjacent coastal ocean. However, a substantial portion of the glacier‐sourced nutrients may be removed by rapid settling of debris (sediments) at the heads of these fjords, before they can be used by marine life. This study analyzes the chemistry of fluids within sediments collected from Patagonian fjord near river and glacial inputs to investigate the fate of glacier‐sourced nutrients (silicon and iron) that have been transferred to the fjord floor. Our laboratory analysis and calculations reveal that biological, chemical and geological processes in these sediments release significant amounts of iron back into the overlying fjord waters, but these high levels of iron chemically bind silicon, restricting its release into fjord waters. The disproportionate release of the two nutrients from fjord sediments found in this study advances our understanding of the modes of supply of glacier‐sourced nutrients to fjords and the coastal ocean. Schematic shows the coupling of benthic Fe and Si cycling, and the inferred spatial difference in the supply of easily reducible Fe (oxy‐)hydroxides and the intensity of pore water advection between the fjord sites. Adsorption of Si onto Fe (oxy‐)hydroxides and co‐precipitation of amorphous Fe‐Si phases occur under relatively oxic conditions in the upper sediments, while Si is released back to solution following the reductive dissolution of Fe in the ferruginous zone. Circles with brighter colors and solid outlines represent solid‐bound Si and Fe(III) phases, while circles with lighter colors and dashed outlines represent dissolved Si and Fe2+phases.

I play in the National Gay Football League, and am happy to say that it bears no relation to Shazia Mirza's experience (11 December). I am proud to say that [...]

As someone who was once 30 pounds overweight, I can appreciate the work Kelly Brownell, Ph.D., does on eating disorders, and I hope that he can help those who are […]

Clad in his standard all-white shorts and Polo shirt, Svend Petersen stands near the pool entrance at the Beverly Hills Hotel and welcomes two guests as if they were Hollywood's [...]

The U.S. Court of Appeals/11th Circuit for southern Florida last month upheld a lower court's decision regarding breach of contract. The court of appeals ruled that Aqua Vac Systems Inc. [...]

Show organizers are hopeful that exhibitor and attendee turnout at the 10th Annual Aqua International Retail Conference & Expo will surpass last year's total. The trade show, scheduled for Feb. [...]

A major hot tub manufacturer says it is frustrated over an inability to distribute its product due to a criminal case in which it plays no role. Cal Spas, based [...]

After considering offers from more than two dozen cities, the International Swimming Hall of Fame has chosen Hollywood, Fla., as the site of its new swimming complex and museum, according [...]

With attendance at the World Waterpark Association's 21st Annual Symposium and Trade Show down substantially, exhibitors said it was a feast-or-famine event. Overall attendance at the show, held Oct. 9-13 [...]

In the last few weeks, New Yorkers from all walks of life have joined together to aid fellow citizens in the face of unspeakable tragedy. While their unity has inspired [...]

The hijacked airliners that crashed into New York's World Trade Center and the Pentagon in Washington, D.C., on Sept. 11 did not directly affect any aquatics facilities or waterparks. Industry [...]

Four high school pools in I a school district in St. Cloud, Minn., soon will have a 'third eye' watching over, under and around swimmers. The pools will be the [...]

Lifeguarding is serious business, but that doesn't mean training for emergency situations can't be fun. That's the attitude at The Colony Aquatic Center in The Colony, Texas. Board games, scavenger [...]

Broward County, Florida, concerned citizens, government officials and aquatics professions created, in 1998, Swim Central, a water-safety education program for preventing drowning of very young children. More than 22,000 preschoolers and kindergartners have learned to swim through the program.