Humans are land-loving creatures and we intuitively understand that seasons are times of change; these transitions are often signaled by cues like day length or temperature. Organisms use seasonal cues like these to time events in their life cycle that maximize survival, growth, and successful reproduction. The timing of life cycle events to coincide with seasonal environmental factors is called phenology<\/strong>. For example, many insects, birds, and small mammals reproduce in the spring to maximize the number of warm months to grow and accumulate resources before a harsh, cold winter. We also see several examples of insect species that have co-evolved with plant species, such that insect larvae are born in synchrony with plant prey species is present or blooming. <\/p>\n\n\n\n In the ocean, we see several similar phenological patterns though the seasonal cues can be different. Most marine organisms have complex life cycles<\/strong>, where nearshore, bottom-associated adults spawn very small, dispersive larvae that feed in the water column for days to months before returning to the nearshore to settle, grow, and reproduce. Many fish and invertebrate species time their reproductive events such that their larvae are feeding in prey-rich conditions. Marine larvae are small organisms, often less than 10mm in length, and so they feed on very small prey items, such as phytoplankton and zooplankton (microscopic drifting plant and animal organisms). Similar to plants on land, many phytoplankton species bloom in the springtime, when day length increases and sunlight penetrates deep into the ocean. Zooplankton populations grow when there is an abundance of the phytoplankton they feed on, and fish and invertebrate larvae populations boom in response. Sunlight and food web cues play a large role in determining the phenology of marine organisms. <\/p>\n\n\n\n It is also necessary to consider that marine organisms exist in a dynamic fluid environment. Wind, currents, tide, and coastline features are all important in determining patterns of water movement in any given area. Because marine larvae are very small, they often travel or disperse with the dominant pattern of regional water movement. Many fish species are thought to time their reproduction not only according to sun-related cues, but also to water movement-related cues such that their larvae are retained in areas with favorable habitat (e.g. a nearshore rocky reef or kelp bed). Additionally, ocean conditions change dramatically along the coastline. For example, prevailing wind patterns in northern California are drastically different from wind patterns in central and northern Oregon, resulting in an abrupt change in nutrient input, phytoplankton productivity, and water movement patterns \u2013 all cues that marine organisms are tuned in to! Understanding phenology in the ocean requires an understanding of seasonality in the food web, seasonality in water movement patterns, and how these patterns are variable in space. <\/p>\n\n\n\n A major part of my dissertation research\nfocuses on better understanding the phenology of marine fish life cycles. I\nstudy the most vulnerable life stages of the fish life cycle (larvae and juveniles,\nwhich are known to experience very high mortality rates) to better understand how\nfood web interactions and water circulation patterns are different along the Oregon\ncoast and throughout the year. My ultimate goal is to use the information I\ngain from my research to improve predictions about the future status of fish\npopulations, especially as ocean conditions are changing. <\/p>\n\n\n\n As I reflect on the importance of ocean\nseasons on the lives of marine fishes, my study organisms, I realize that as a\nstudent of marine science I also depend on ocean seasons. In Oregon, the April-September\nmonths are marked by a transition to nutrient and phytoplankton rich waters (known\nas upwelling) and many larval and juvenile fish species are present in the\nnearshore waters. After September, the ocean transitions in to a relatively nutrient\nand phytoplankton poor state (known as downwelling) that lasts until the\nfollowing April. The winter months also have larger storms, night tides, and\nless sunlight, making field work and sampling more difficult. These seasons are\nreflected in my work student as well: from April-September, I spend most of my\ntime collecting samples, going on oceanographic research cruises, and organizing\na team of dedicated undergraduates to conduct field work. By the time October comes\naround, most of my activities are land and office-based. This is a welcome\nchange of pace after a busy summer season. This fall quarter was a special time\nfor me because I passed my oral exams! This marks the completion of most of my\ncoursework and the last major checkpoint in my program before my dissertation\ndefense. As we transition into the winter term, I\u2019m very excited to present other\nparts of my dissertation work to the Oregon Department of Fish and Wildlife\nMarine Reserves Program, and at an international conference in Japan. I\u2019m also\nlooking forward to teaching an introductory biology lab course, expanding my\noutreach opportunities, and preparing for another summer of field work! <\/p>\n","protected":false},"excerpt":{"rendered":" How are ocean and terrestrial seasons different? Humans are land-loving creatures and we intuitively understand that seasons are times of change; these transitions are often signaled by cues like day length or temperature. Organisms use seasonal cues like these to … Continue reading My dissertation research focuses on phenology of marine fish life cycles.<\/h2>\n\n\n\n
As a student of the ocean, my schedule aligns with ocean seasons.<\/h2>\n\n\n\n