Sperm whales (Physeter macrocephalus) emit short, broadband clicks which often include multiple pulses. The time interval between these pulses [inter-pulse interval (IPI)] represents the two-way time for a pulse to travel between the air sacs located at either end of the sperm whale's head. The IPI therefore, is a proxy of head length which, using an allometric relationship, can be used to estimate total body length. Previous studies relating IPI to an independent measure of length have relied on very small sample sizes and manual techniques for measuring IPI. Sound recordings and digital stereo photogrammetric measurements of 21 individuals were made off Kaikoura, New Zealand, and, in addition, archived recordings of whales measured with a previous photogrammetric system were reanalyzed to obtain a total sample size of 33 individuals. IPIs were measured automatically via cepstral analysis implemented via a software plug-in for pamguard, an open-source software package for passive acoustic monitoring. IPI measurements were highly consistent within individuals (mean CV=0.63%). The new regression relationship relating IPI (I) and total length (T) was found to be T=1.258I+5.736 (r(2)=0.77, p<0.001). This new regression provides a better fit than previous studies of large (> 11 m) sperm whales.

A healthy marine environment is integral to numerous New Zealand economic, social, and cultural values, including fisheries, aquaculture, tourism, and recreational and customary activities. The introduction and spread of marine non-indigenous species (NIS) via the vessel biofouling pathway may put these values at risk. Over the past two decades, the Ministry for Primary Industries (MPI) has been proactive in commissioning research focused on the risks associated with vessel biofouling, identification of potential risk vessels, and risk management options. In 2010, MPI consulted on options to manage the biofouling risks on all vessels entering New Zealand waters. In 2014, New Zealand became the first country to introduce mandatory biofouling requirements. Between 2014 and 2018, MPI focused on communicating the requirements to support stakeholder awareness, readiness, and uptake. In parallel, MPI commissioned further research to investigate proactive and reactive approaches to biofouling management. Research outcomes were summarized and technical advice provided to inform stakeholders of what constitutes best biofouling management practices. This review summarizes MPI's research and technical advice on the risks associated with vessel biofouling and its management, and the procedures followed to produce New Zealand's biofouling regulations. The development of these regulations is also contextualized in terms of New Zealand's marine biosecurity system. The transparent and evidencebased approach followed by MPI provides a blueprint for establishing biofouling regulations. Because these regulations are aligned with the International Maritime Organization guidelines, there is the potential to develop consistent global and domestic practices for managing marine NIS introduction and spread.

A non-invasive acoustic method for measuring the growth of sperm whales was developed based on estimating the length of individuals by measuring the inter-pulse interval (IPI) of their clicks. Most prior knowledge of growth in male sperm whales has come from from fitting growth curves to length data gained from whaling. Recordings made at Kaikoura, New Zealand, were used to estimate the length and growth of 32 photographically identified, resident whales that have been recorded repeatedly between 1991 and 2009. All whales recorded more than six months apart (n = 30) showed an increase in IPI. Using established relationships between IPI and total length, it was found that the average growth rate in the Kaikoura population is lower, especially for smaller whales (13-14.5 m), than that derived from historical whaling data from other populations. This difference may be due to ecological differences among populations but might also reflect upward bias in measurements gained in whaling. The ability to track growth of individuals through time is only possible via non-lethal means and offers a fundamentally different kind of data because differences among individuals can be measured.

Sea chests are cavities built into a vessel's hull to aid the efficiency of pumping seawater into internal pipework systems. Sea chests and internal pipework are known hotspots for the accumulation of biofouling, and vessel biofouling is a major pathway for the introduction and spread of nonindigenous marine species. The use of preventive strategies to minimize biofouling within sea chests and internal pipework is difficult due to their structural complexity; therefore, reactive methods to manage the associated biosecurity risk are required. This review examines the efficacy, environmental considerations, and cost of different systems to reactively manage sea chest and internal pipework biofouling within operationally realistic time frames (<3 days) and identifies those that warrant further investigation. Physical removal systems with recapture capability should be developed for accessible areas (e.g., grates), as such systems provide an operational benefit to the vessel. For internal and inaccessible surfaces, the development of thermal systems, particularly steam systems, is encouraged as they offer broad-spectrum efficacy at obtainable temperatures and require relatively short exposure periods. Compared to chemical treatments, thermal treatments are less influenced by environmental variables (e.g., temperature, water chemistry) and regulatory constraints.

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